Question

qual e o resultado de x+y=13
                                   x+5y=29 ?

Answer 1

(1) x+y=13
(2) x+5y=29

x=13-y (isolei o x do 1)
13-y+5y=29 (apliquei no 2)
13-4y=29
4y=16
y=16/4
y=4

x+4=13
x=13-4
x=9