Question

{×+y=10
×=y-30

{2×+y=-5
x-y=20

{3×+=2
x-y=6
​

Answer 1

Resposta:

a)

{x+y= 10

{x= y-30

x+y= 10

y-30+y= 10

2y= 10+30

y= 40:2

y= 20

x= y-30

x= 20-30

x= -10

b)

{2x+y= -5

{x-y= 20

x-y= 20

x= 20+y

2x+y= -5

2(20+y)= -5

40+2y+y= -5

3y= -5-40

3y=-45

y= -45:3

y= -15

x-y= 20

x- 15= 20

x= 20+15

x= 35

c)

{3x+= 2 (falta dados) nao deu pra responder

{x-y= 6

Explicação passo-a-passo: