Question

Solve.

{y=x−75x+2y=7

Use the substitution method.

(3, −4)

(−1, −8)

(7, 0)

(0, −7)

Answer 1

`\left\{\begin{array}{ccc}y=x-7\\5x+2y=7\end{array}\right\\\\\text{subtitute the value of y to the second equation}\\\\5x+2(x-7)=7\\5x+2x-14=7\\7x-14=7\ \ \ |+14\\7x=21\ \ \ \ |:7\\x=3\\\\\text{subtitute the value of x to the first equation}\\\\y=3-7=-4\\\\\boxed{\text{x=3;\ y=-4}\to(3;\ -4)}`

Answer 2

Here is the CORRECT answer.