Respostas

2014-01-15T19:24:46-02:00
A)
 x  = 72
10      5
5x = 72 * 10
5x = 720
x = 720 ÷ 5
x = 144

b)
9  = 27
y      3
27y = 9 * 3
27y = 27
y = 27 ÷ 27
y = 1