Question

X + Y = 10 2x + Y = 7

Answer 1

x+y=10

2x+y=7

x=10-y

20-2y+y=7

-y=7-20

-y=13

y=13

x+13=10

x=10-13

x=-3

Answer 2

olá.

x+y=10

2x+y=7

x=10-y

2x+y=7

  ↓

2·10-y+y=7

2y+20+y=11

2y+20+y=11

2y+y=11-20

3x=-9

x=-9/3

x=-3

-3·7=13
y=13

espero ter te ajudado

bons estudos

=D