Question

Solve this system of equations using subtraction
4x - 4y = -4
4x + y = 21

Answer 1

Answer:

x = 4

y = 5

hope you find this helpful.

Answer 2

Answer:

line 1: 4x +4y =12 or x+y=3 or y=3-x

line 2: x-7y=-21

line2...x-7*(3-x)=-21

x+7x -21 =-21

8x=0

x=0

y=3-x =3