Question

a) {×-y=-7
{×+y=29

B) {2×+ 3y=20
{×-y=-5

Answer 1

Resposta:

x-y=-7

x+y=29

2x=22

x=11

x-y=-7

11-y=-7

-y=-7-11(-1)

y=18

b)2x+3y=20

x-y=-5 (-2)

2x+3y=20

-2x+2y=-10

5y=10

y=10/5

y=2

x-y=-5

x-2=-5

x=-3