Respostas

2014-06-22T12:10:10-03:00
x - 3 (4-x) = 7x - (1-x)  
x -12 + 3x = 7x -1 +x   
x  - x + 3x -7x  = 12 - 1
-4x = 11
x = -11/4

1 + 2x = 3 - 5x
2x +5x = 3 - 1
7x = 2
x = 2/7
2014-06-22T12:18:15-03:00
x-3(4-x)=7x-(1-x)
x-12 +3x=7x-1+x
x+3x -7x-x= -1 +12    cancela o x positivo com o x negativo.
-4x = 11  .(-1)
 4x = -11
   x = -11
           4

1 +2x=3 -5x
2x +5x= 3 -1
7x = 2
  x = 
         7