Question

x/y=3/4 e x+y=21 alguem sabe montar?

Answer 1

x/y=3/4
x+y = 21

x/y = 3/4
4x = 3y
x = 3y/4

x + y = 21
3y/4 + y = 21
3y+4y/4 = 21
7y/4 = 21
7y = 84
y = 12

x + y = 21
x + 12 = 21
x = 9