Respostas

2014-02-26T10:54:21-03:00
A)X=10+3
X=13

B)X=-16/2
X=-8

C)2X+3.9(X-5)=4X+9
2X+3.(9X-45)=4X+9
2X+27X-45=4X+9
29X-4X=9+45
25X=54
X=54/25
X-~2,16

D)2.(X+1)-3(2X-5)=6X+3
2X+2-6X+15=6X+3
2X-6X-6X=3-15-2
-10X=-12-2
X=-10/2
X=-5