Question

Plmds preciso hoje gente pfvrrr

Answer 1

Resposta:

x-y=5

x+y=7 >>>> x+y-y=7-y >>> x=7-y

substituir em x-y=5....

(7-y)-y=5

7-y-y=5

7-7-2y=5-7

-2y=-2 (÷ -2)

y=1

x-y=5

x-1=5

x=6