I'm really confused about this question about Solving Systems by Elimination

x-y=8
x+y=12

x=10

y=2

Step-by-step explanation:

1)add the equations and find what x is.

x-y=8

+x+y=12

—————

2x=20

— —

2 2

x=10

3)fill in x for the second equation.

x+y=12

since x=10,replace x with 10.

10+y=12.

subtract 19 from both sides.

10+y=12

-10 -10

—————-

y=2

s

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.