Question

Resolva :
-3 (1-2x) = 12-3y

3(x+2)=-(x+1)

2(3-x)=3 (2x+1)

Answer 1

a)

- 3.(1- 2x) = 12 - 3x
- 3 + 6x = 12 - 3x
6x + 3x = 12 + 3
9x = 15
x =   15  (:3)
       ------
         9   (:3)

x =   5
       ----
        3

b)

3.(x + 2) = -(x + 1)
3x + 6 = - x - 1
3x + x = - 1 - 6
4x = - 7
x = - 7/4


c)

2.(3 - x) = 3.(2x + 1)
6 - 2x = 6x + 3
6 - 3 = 6x + 2x
3 = 8x
8x = 3
x = 3/8