Question

Valores do sistema x-y=+1 2x7y=28

Answer 1

x-y=1
x=1+y

2x+7y=28
2(1+y)+7y=28
2+2y]+7y=28
9y=26
y=26/9

x=1+y
x=1+26/9
x=(9/9)+(26/9)
x=35/9

Teste:

x-y=1
(35/9)-(26/9) = 1
9/9=1
1=1