Question

resolva osbl seguinte sistemas

x+y=28
x-y=4

Answer 1

Olá,

x+y=28
x-y=4

x=28-y

28-y-y=4
-2y=4-28 (-1)
2y=-4+28
y=24/2
y=12

x=28-12
x=16

Espero ter te ajudado!

Answer 2

x+x+y-y=28+4
2x=32
x=32/2
x=16


x+y=28
16+y=28
y=28-16
y=12