Respostas

2013-12-04T18:38:26-02:00
X+y = 45 → x = 45-y
x/y = 2/7 → 7x = 2y

7(45-y) = 2y
315-7y = 2y
2y+7y = 315
9y = 315
y = 315/9
y = 35

x+y = 45
x+35 = 45
x = 45-35
x = 10