Respostas

2013-09-05T15:15:39-03:00
4(x+5) + 3(x+5) = 21
7(x+5) = 21
x+5 = 3
x = 3-5 = -2
4 3 4
2013-09-05T15:25:44-03:00
4(x+5)+3(x+5)=21
4x+20+3x+15=21
4x+3x=-20-15+21
7x=1-15
7x=14
x=14/7=2

3 5 3