Question

mim ajudem pfvr presiso disso pra hj ​

Answer 1

Tá aí.

Agora ajuda eu, bota melhor resposta ✌

Answer 2

a) x+y=20

x-3y=-12

2x-2y=8

2x=8+2y

x=8+2y/2 :2

x=4+y

4+y+y=20

4+2y=20

2y=20-4

2y=16

y=16/2

y=8

x=4+8

x=12

b) x+y=40

4x+2y=140

x=40-y

4(40-y)+2y=140

160-4y+2y=140

-2y=140-160

-2y=-20 (-1)

2y=20

y=20/2

y=10

x+y=40

x+10=40

x=40-10

x=30

x+y=40

10+30=40