Question

calcular os sistemas: x-y=40   3x-2y=80

Answer 1

x-y=40
3x-2y=80

x=40+y

3x-2y=80
3*(40+y)-2y=80
120+3y-2y=80
120+y=80
y=80-120
y=-40

Achando o valor de x:

x=40+y
x=40-40
x=0