Question

me ajuda matemática...​

Answer 1

Resposta:

a) x+y=9 x-y=5

y=9-x x-(9-x)=5

x-9+x=5

x+x=5+9

2x=14

x=14/2 x=7

y=9-x

y=9-7

y=2

b)x+y=7 4x-y=8

x=7-y 4(7-y)-y=8

28-4y-y=8

28-8=4y+y

20=5y y=20/5 y=4

x=7-y

x=7-4

x=3