Question

resolva os sistemas ×+¥=20 ×-¥=8

Answer 1

(I) + (II)

2x = 28

x = 14

14 +y = 20

y = 6

{14 , 6}

Answer 2

x+y=20
x-y=8

2x=28

x=28/2

x=14


y=-8+x

y=-8+14

y=6

espero ter ajudado!