[Context] I make this project for @zorg06 who asks me how to solve this equation, and which way was the fastest. [INFOS] Speed test for three different ways to solve this equation. Those ways are : - 1st, the "normal" that correspond to the one you learn in highscool of before, which where you replace x, then y, ten x. - 2nd, the Gauss's pivot - 3rd, the matrices As you can see, solve this equation using matrices is faster than Gauss's pivot, which is faster than the "normal" resolution. Details inside.