Question

PLEASE HELP ASAP!

Solve the system of equations using substitution.

y = 2x – 10
y = 4x – 8

(–1, –12)

(3, –4)

(–4, –17)

(3, 4)

Answer 1

ok so I will take this from the top, lets start out  with choice A (-1,-12) we will need to see if the answer is equal to A. so first lets just merge these two problems into eachother to get 4x-8=2x-10 now, after subtracting 2x from each side we get 2x-8=-10. Now, add 8 to both sides which will give us 2x=-2... now it is simple, just divide -2 by 2 to get an answer for x as -1...Answer A is the correct answer

Answer 2

$\begin{cases}y=2x-10\\y=4x-8\end{cases}\\\\\\ 4x-8=2x-10\\\\4x-2x=-10+8\\\\2x=-2\qquad|:2\\\\\boxed{x=-1}\\\\\\y=2x-10\\\\y=2\cdot(-1)-10\\\\y=-2-10\\\\\boxed{y=-12}\\\\\\\begin{cases}x=-1\\y=-12\end{cases}$

Answer A)