Question

x+y=7;x-y=1
3x-y=10; x+y=18

Answer 1

Explicação passo-a-passo:

2×=8

×=8/2

×=4

×+y=7

4+y=7

y=7-4

y=3

×=18-y

3.(18-y)-y=10

54-3y-y=10

-3y-y=10-54

-4y=-44(-1)

4y=44

y=44/4

y=11

×=18-y

×=18-11

×=7