Answer:
x = 9
Step-by-step explanation:
1) Subsitute! You have to replace y with 2x - 2 in 3x -y = 7, b/c they already gave you the equation for y (in the second part: y = 2x - 2)
So, your equation would look like this : 3x - (2x - 2) = 7
3) Solve suing PEMDAS!
There's a negative outside the parenthesis of 2x -2 -> - (2x-2). Multiply the negative individually inside the parenthesis so you will get (-2x + 2)
3x - 2x - 2 = 7 subtract the same variable; x
1x - 2 = 7 you don't need to put 1 to x, only if you want!
+ 2 + 2 add 2 on both sides
x = 9
