10x − 8y = 10 10x − 7y = 20

Answer 1

10x − 8y = 10

-(10x − 7y = 20)

-10x+7y=-20

10x − 8y = 10

Add equations together

-y=-10

Multiply both sides by -1

y=10

10x − 8y = 10

substitute y=10

10x-8(10)=10

10x-80=10

Add 80 to both sides

10x=90

Divide by 10

x=9