Respostas

2013-09-10T20:24:54-03:00
10x - 7x = 20+ 7 -3
3x= 24
x =8
2013-09-10T20:29:09-03:00
10x -20 = 7x+7-3
10x- 7x= +7 -3 +20
3x= 24
x=24/3
x=8