Respostas

2013-11-18T19:20:23-02:00
Tais ---> x

 x  + 4  = 2x - 21  ==> mmc = 3
 3

x  + 12  =  6x  -   63
 3     3        3         3 

x + 12 = 6x - 63

x - 6x = -63 -12
-5x = -75 (-1)
5x = 75
x   = 75 : 5 

x = 15
1 5 1