You can solve 3 equations having 3 variables. Here are the 3 equation examples: x+2y+z=10. 2x-y+3z=-5. 2x-3y-5z=27. The goal is to reduce to 2 equations having 2 variables. Multiply bottom equation by (-1). Rewrite 2nd and 3rd equation. 2x-y+3z=-5. Add -2x+3y+5z+-27. Equals 2y ...more

This video shows you how to set environment variables in Windows XP. A lot of the older software written for windows requires the use of environment variables. There are variables set at the system level and programs that run in a DOS window or older programs can access these ...more

Welcome back, my aspiring hackers! One of the areas that often gives Linux newcomers problems are the environment variables. Although Windows systems have environment variables, most users, and for that matter, most administrators, never manage their environment variables. To ...more

Hello again, reader! In this post, we are going to cover some data types and how to declare variables. It shouldn't be too hard so just sit back, relax, grab some popcorn and enjoy the ride (while you still can!). What Is a Variable? For those who do not know, a variable is ...more

Using variables allows your Lego Mindstorms NXT robot to store numbers or text based on input. Learn how to program variables using the NXT programming environment. Program variables in the Lego Mindstorms NXT system. Click through to watch this video on ortop.org

This clip offers an introduction to using attributes and local variables in Houdini. It covers vertices (vertexes), points, primitives and details. Whether you're new to Side Effects Software's popular 3D production program or a seasoned graphic artist just interested in bette ...more

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next ...more

Want to simplify a radical expression with algebraic variables? See how it's done with this free video algebra lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks t ...more

Welcome back my friends !! Today we'll go through the second part of this C# series Let's start!! Last time we left off with Console.WriteLine and Console.ReadKey now we'll combine these with some variables and comments. Comments are useful for multiple reasons: for exemple ...more

In python, or any scripting language for that matter, there are certain things that you will carry with you throughout your entire scripting career. Some of the most basic things that you will keep with you are output, variables, and their value types. We'll start by going ove ...more

Java works a little differently than languages like Python or PHP when it comes to working with variables. This tutorial shows you what the difference is, how you can define your variables and the easiest ways to work with them when writing programs in Java.

Variables are the core of nearly any programming language, and Python is no different. This tutorial shows you how to work with variables when you're starting to program in Python. This also shows you how to get familiar with the shell in Python.

Not all inequalities are created equal. See how to solve three of the most common types with this free video algebra lesson, which discusses regular, negative and mixed-variable inequalities. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and ...more

In basic algebraic equations all the variables are on left side of the equation. But as the complexity of the problems increases you will find that the equations will contain variables on both sides of the equation. To solve these kinds of problems first simplify the equations ...more

Looking for a primer on how to multiply varibles with rational exponents? Look no further. This free video algebra lesson will show you how it's done. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belong ...more

Encryption is the process of converting you data in to other obscure form so that no one can read it. Encryption can also be done using batch files. Batch files are scripting programs in windows which can be used to program small automatic operations. To do this open a notepad ...more

An educational video from Math Problem Generator that shows how to multiply variables. It is a very short video - about 1 min in length. This video is really for kids who have just started their algebraic variable classes. This video takes two variables of x along with their ...more

Math Problem Generator gives a video about how to add and subtract variables. All you have to do is combine the coefficient, which is the number that comes before the variable. The numbers are added or subtracted but the variable remains the same. In the video, the example giv ...more

Bucky from The New Boston serves up this Python video tutorial on how to program variables in Python. This is the program you use to write all of your Python code down. Fun with variables! Python is a dynamic, object-oriented, high-level, programming language that can be used ...more

In this article, I'll be exploring the basics of Python, i.e. variables, input and output. You'll need Python (2.7+), a computer, and some free time. Variables Simply put, variables are like envelopes. They are empty and meaningless until we place objects and meaning into th ...more

In this clip, you'll learn the ins and outs of using variables and strings when writing code in Python 2. Whether you're new to the Python Software Foundation's popular general purpose programming language or a seasoned developer looking to better acquaint yourself with the fe ...more

Looking for a primer on how to work with BRIEF probability density functions and continuous random variables in calculus? Learn how with this free video calc lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical mi ...more

This tutorial provides some more useful information for PHP beginners. You'll get a quick overview about post, get and request superglobal variables. From this you'll learn how to handle a URL and a form. Don't be shy, jump in and see if PHP is right for you.

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps. For all of the details, watch this installment from ...more

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps. With this installment from Internet pedagogical sup ...more

Need help figuring out how to solve an equation with given variables in algebra? Learn how with this free video math lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, th ...more

Need help reducing fractions containing algebraic variables? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it' ...more

If you use Microsoft Excel on a regular basis, odds are you work with numbers. Put those numbers to work. Statistical analysis allows you to find patterns, trends and probabilities within your data. In this MS Excel tutorial from everyone's favorite Excel guru, YouTube's Excel ...more

Learn how to find all your global expression variables within Houdini.

Before I start a series on remote exploitation, I think we should learn the basics of Perl. Perl, Ruby, C, C++, Cython and more are languages that some penetration testers just need to learn. Perl is a great language for multiple things, sadly, like many other scripting langua ...more

Want to program your own Java games and applications but don't know beans about object-oriented programming? Never you fear. This free video tutorial from TheNewBostonian will have you coding your own Java apps in no time flat. Specifically, this lesson discusses how to multip ...more

This video is aimed at beginner level viewers and shows one of the basic techniques involved while solving linear equations having one variable. This method finds it use when the variables and constants are present on both sides of the linear equation to be solved. As shown ...more

In order to simplify complex variables, you must first consider the numerical values separate from the variable. In the case of 24x/48x, you would look at the numbers alone to see if they have any factors. These numbers have the number 6 in common. So, divide it by 6. This wil ...more

This is a helpful video provided by Math Problem Generator. It deals with the complex challenges of dividing variables. The audio is great and provides specific examples of dealing with multiple types of this problem. The video lays out three simple steps. The first being to s ...more

Bucky from The New Boston serves up this Python video tutorial on how to overwrite variables on a subclass in Python. This is the program you use to write all of your Python code down. Fun with subclasses! Python is a dynamic, object-oriented, high-level, programming language ...more

Welcome back, everyone! In this lesson, I'm going to go over the use of the echo function and variables, as well as basic syntax. You will need: A text editor - I personally recommend the free (and amazing) Notepad ++, but you can use any text editor you want, even Windows' ...more

In the video, the process of factoring trinomials is described. A trinomial that cannot be easily factored in its original form is shown. It is simplified by pulling out the greatest common factor. After that, a trinomial that is easier to factor is shown. Next, the simplified ...more

Confused in math class and need some extra help? This educational video gives instruction on how to solve mathematical algebraic equations. It shows you how to break an equation down and make them less scary to solve. Step-by-step instructions show you how to solve more compli ...more

This video is a great one on learning about evaluating fractions. The voice explains how to first plug in the numbers given for each variable in the fractions. He also explains the importance of simplifying the top and bottom first before simplifying the entire fraction. He al ...more

What's up readers? We have ever so slightly touched upon this concept of scope with variables but still don't really know what it means. In this tutorial we will learn the behaviors of variables existing in our programs and within functions. What Is a Variable Scope? A scope ...more

Welcome back Java programmers! In this tutorial we'll being going over Variables/DataTypes and Type-casting So What Are Java DataTypes? Like in many other programming languages, you have variable types. Such as ints, doubles, chars, etc. They are used to instantiate the kind ...more

Get a crash course on HScript Expressions, Variables, and Attributes in Houdini 10. If you don't even know what this means, then you probably need to check this video tutorial series out. Understanding how to massage data in Houdini is key to giving yourself the creative edge ...more

In order to combine like terms, you need to look at the variables. Terms can only be combined if the variables are all identical. The first thing that you would have to do is look for matching variables. In the example, x + 2x5 + y2 - 9x - 2x5 + 5y2, you should try to see whic ...more

Exponential functions are functions which contains terms which are integers raised to the power of variables. Note that the variables are not raised to the power of integers, but the integers are raised to the power of variables. Variables raised to the power of integers are c ...more

In previous tutorials we have encountered these things called pointers and addresses but we still don't know what they really are. Let's learn a bit more to clear things up. What Are Pointers and Addresses? A pointer is a type of variable which as been combined with the dere ...more

In the last tutorial, we learned how to make functions and how they work on the high level. This time, we will take a peek under the hood again, stare deep into its soul and see its ugliness face to face to see how it works in the lower level. The Code Segment The code segme ...more

When we are building programs that communicate over a network, how can we keep our data private? The last thing we want is some other lousy hacker sniffing our packets, so how do we stop them? The easy answer: encryption. However, this is a very wide-ranging answer. Today we'r ...more

Welcome back, my greenhorn hackers! Recently, I asked the Null Byte community what subject they would most like me to cover in future tutorials. Many of you cited scripting, and I decided it's best to cover this subject soon, so here goes. Any self-respecting hacker must be ...more

When the climate changes, so do all the things that rely on the climate, including people, plants, and pathogens. A European study recently took a broad look at what kind of microorganisms are most likely to be affected as climate change heats, cools, dries, and wets the world ...more

Welcome back to another tutorial on functions. Last time, we looked inside memory to see what functions looked like in the flesh and all that Assembly was pretty nasty. At least you have some exposure to it. This time, we will be examining how functions work with the stack. E ...more

While hackers know and love the Raspberry Pi, many don't know of its cheaper cousin, the microcontroller. Unlike a Pi, which can be used more or less like a regular computer, microcontrollers like the Wi-Fi connected ESP8266 require some necessary programming skill to master. ...more

All the files you need are in a free download on DevelopPHP. PHP has to be on a server. It will not run on a local machine. Type your name. There are two variables which show up in the dialog boxes (which are stacked.) You can change the user name. It sets up a URL request and ...more

In this video the instructor shows who to simplify radicals. If you have a term inside a square root the first thing you need to do is try to factorize it. First factorize the numerical term. Write down the numerical terms as a product of any perfect squares. Now split the ori ...more

Hello there! This will probably be the final tutorial on functions where we will be looking over a method called pass by reference. This technique allows us to modify large amounts of data without the overhead and return multiple values. Let's go! Passing by Value Until now, ...more

Hello everyone. I've recently made the annoucement of the Null Byte suite of tools, and we've covered how to download and install it. Now it's time we cover how to submit a tool for inclusion into the suite. It's relatively simple, but we need to get a few ground rules out of ...more

Hello my fellow hackers, Welcome to my republished revision of the ruby programming language, Part 1. Today, we will try to build an ftp cracker in ruby: This is going to be a quick one since OTW has already made one in python and we are gonna look upon that to create a simil ...more

After a long hiatus, we shall once again emerge from the shadowy depths of the internet to build an exploit. This time, we'll be looking at how to defeat a non-executable stack by using the ret2libc technique — a lean, mean, and brilliant way of exploiting a stack overflow vul ...more

Before I continue with a topic on strings, we first require some fundamental understanding of how memory works, i.e. what it is, how data looks in memory, etc. as this is crucial when we are analyzing vulnerabilities and exploitation. I highly suggest that your mind is clear a ...more

Welcome back, my rookie hackers! I recently began a series on using Metasploit, and my goal with it is to teach you the very basics the incredibly powerful hacking tool has to offer while progressively moving on to the more advanced features. In my first Metasploit installme ...more

While our time with the Protostar VM from Exploit Exercises was lovely, we must move on to bigger things and harder challenges. Exploit Exercises' Fusion VM offers some more challenging binary exploitation levels for us to tackle. The biggest change is that these levels are al ...more