Respostas

2014-08-28T18:44:41-03:00
9+2(5x-4)=21
9+10x-8=21
10x=21-1
10x=20
x=20/10
x=2
1 5 1
2014-08-28T18:45:10-03:00
9+ 10x- 8= 21
10x=21-9+8
10x = 20
x = 20 / 10
x= 2