Respostas

2014-06-09T00:06:26-03:00
 A)  10b-2.(b+4)=3b+7 
10b - 2b - 8 = 3b + 7
10b - 2b - 3b = +7 + 8
5b = 15
b = 15/5
b = 3

B)    13x+1-10x=5+x
13x - 10x - x = 5 - 1
2x = 4
x = 4/2
x = 2