Question

Resolva as equações:

a) 2 x + 5 = 27

b) 4 x - 8 = 2 x + 6

c) 7 x + 1 = 6 x + 6

d) 5 x - 3 = 2 x - 9

e) 4 x - 7 + x = 1

f) 3 - 2 x = 4 x

g) 9 - x = x + 10

h) - 2 x + 7 = 4 x + 5

i) 3 x - 20 = x + 80

j) 5 x + 50 = 3 x + 290

Answer 1

a) 2x + 5 = 27
2x = 27 - 5
2x = 22
x = 22/2
x = 11

b) 4x - 8 = 2x + 6
4x - 2x = 6 + 8
2x = 14
x = 14/2
x = 7

c) 7x + 1 = 6x + 6
7x - 6x = 6 - 1
x = 5

d) 5x - 3 = 2x - 9
5x - 2x = - 9 + 3
3x = - 6
x = - 6/3
x = - 2

e) 4x - 7 + x = 1
4x + x = 1 + 7
5x = 8
x = 8/5

f) 3 - 2x = 4x
- 2x - 4x = - 3
- 6x = - 3 (-1)
6x = 3
x = 3/6
x = 1/2 ou x = 0,5

g) 9 - x = x + 10
- x - x = 10 - 9
- 2x = 1 (-1)
2x = - 1
x = - 1/2 ou x = - 0,5

h) - 2x + 7 = 4x + 5
- 2x - 4x = 5 - 7
- 6x = - 2 (-1)
6x = 2
x = 2/6
x = 1/3

i) 3x - 20 = x + 80
3x - x = 80 + 20
2x = 100
x = 100/2
x = 50

j) 5x + 50 = 3x + 290
5x - 3x = 290 - 50
2x = 240
x = 240/2
x = 120

Answer 2

a) 2 x + 5 = 27
    2x = 27 - 5
   2x = 22
   x = 11

b) 4 x - 8 = 2 x + 6
     4x - 2x = 6 + 8
     2x = 14
    x = 7

c) 7 x + 1 = 6 x + 6
    7x - 6x = 6 - 1
      x = 5

d) 5 x - 3 = 2 x - 9
    5x - 2x = -9 +3
     3x = -6
     x = -2

e) 4 x - 7 + x = 1
    5x = 1 + 7
     5x = 8
     x = 8/5

f) 3 - 2 x = 4 x
     3 = 6x
     x = 3/6
     x = 1/2

g) 9 - x = x + 10
    -x - x = 10 - 9
    -2x = 1
      x = -1/2

h) - 2 x + 7 = 4 x + 5
        -2x - 4x = 5 - 7
         -6x = -2
           x = 2/6
           x = 1/3

i) 3 x - 20 = x + 80 
    3x - x = 80 + 20
     4x = 100
       x = 25

j) 5 x + 50 = 3 x + 290
   5x - 3x = 290 - 50
     2x = 240
     x = 120