Question

resolva os sistemas:
a) x+y=12
x+2y=3


b)x+y=0
2x-y=6​

Answer 1

Resposta:

a)x=12-y

x+2y=3

1°passo:

12-y+2y=3

-y+2y=3-12

y=-9

2°passo:

x=12-(-9)

x=12+9

x=21

b)x+y=0

2x-y=6

1°passo:

-y=6-2x.(-1)

y=-6+2x

x+6+2x=0

x+2x=6

3x=6

x=6÷3

×=2

2.(2)-y=6

4-y=6

-y=6-4

-y=2.(-1)

y=-2