<span>b is the independent variable ok</span>
In order to use substitution, you need to isolate a variable on one of the equations:
-2x+y=0
y=2x
Then you plug that equation into the other equation. Since we isolated y, we plug in 2x for y in the other equation:
3x-(2x)=5
x=5
Then plug the value you found into any equation to solve for the other variable:
3(5)-y=5
15-y=5
-y=-10
y=10
So your answers are x=5, y=10
180/3x then you get you answer
