Respostas

2014-08-21T11:30:13-03:00
Basta multiplicar cruzado
3x = 7 * 12
3x = 84
x = 84/3
x = 28

2x  =  6
15      9


18x = 90
x = 90/18
x = 5

2 = x+3
9  x-1


9x + 27 = 2x - 2
9x - 2x = -27 - 2
7x = -29
x = -29/7









1 5 1