Respostas

2014-03-28T17:12:02-03:00
A) 5.(x-2)= 20-5x
  5x-10=20-5x
  5x+5x=20+10
  10x=30
  x=30/10
  x=3


b)
3x+5=5.(x-1)
  3x+5=5x-5
  5+5=5x-3x
  2x=10
  x=10/2
  x=5
2014-03-28T18:18:53-03:00
5(X-2)= 20-5X
5X-10=20-5X
5X+5X=+10+20
10X = 30
X= 30/10
X= 3