Solve the system by substitution.
y = 8x – 6
y = 2x

Since both equations equal to y, that would mean that both equations would equal each other. This means that the equation would turn into 2x = 8x - 6. Once you have this equation, you have to move all the terms that have the pronumeral x to the left. So, you would move 8x to the left. In order to do this, you have to minus 8x on both sides, 2x-8x=8x-8x-6. This is equation will simplify to -6x=-6. To find out what x is equal to, you then need to get rid of the -6 by dividing -6 by both sides. In the end, x should equal to 1. Then you need to find out what y is equal to. Since x=1, you can substitute it into one of the equations. Let’s use the equation y=2x. If you substitute x with 1, y should equal to 2. Now you know what y and x equals to.

Answer 20 centimeters15+8=2323-3=20so the answer is 20 centimeters