Respuestas

2014-01-07T23:26:12+01:00
1.
3x -2 + 7x = 7-1
   10x -2 = 6
   10x = 8
    x = 4/5
2.
 8x + 12 - 2x = 4x + 20
 6x - 4x =20 - 12
 2x = 8 =====> x = 4
3.
34 = 5x - 6
34 + 6 = 5x
40 = 5x
8 = x