Respostas

2016-08-15T22:52:54-03:00
1) x + x/2 = 15
2x+x=30
3x=30
x=30/3
x=10

2) x +x/4=20
4x+x=80
5x=80
x=80/5
x = 16

3) x +2x +x/3=30
3x+6x=90
9x=90
x=90/9
x=10