Question

Resolva as equações:

a) 2 (7x + 2) + 12 (x + 1) = 2

b) y + 4 = - 15

c) 3x + 9 = 12

d) x/3 - 7/8 = x/4 - 1

e) 3x - 5 - x - 2 = 7
-------- -------
2 5

f) x/2 + 1/3 = 4

g) x/2 - 5 = x + 3/4

h) -x/3 - x/2 = 2/3

o) 2 + 3x/2 = x + 3/2

Answer 1

a) 2 (7x + 2) + 12 (x + 1) = 2
     14x + 4 + 12x + 12 = 2
      26x = 2 - 12 - 4
      26x = -14
       x = -14/26 = -7/13

b) y + 4 = - 15
     y = -15 - 4
     y = -19

c) 3x + 9 = 12
   3x = 12 - 9
   3x = 3
   x = 3/3 = 1

d) x/3 - 7/8 = x/4 - 1 (mmc: 24)

8x/24 - 3.7/24 = 6x/24 -24.1/24
8x - 21 = 6x - 24
8x - 6x = -24 + 21
2x = -3
x = -3/2

e) (3x - 5) - x - 2 = 7 (mmc:10)
    --------    -------
      2             5

(5.3x - 5.5) /10 - 2x - 2.2/10 = 10.7/10
15x -25 -2x -4 = 70
15x - 2x = 70 + 4 + 25
13x = 99
x = 99/13

f) x/2 + 1/3 = 4  (mmc: 6)
3x + 2 = 4.6
3x = 24 - 2
3x = 22
x = 22/2

g) x/2 - 5 = x + 3/4 (mmc: 4)

2x/4 -4.5/4 = 4x/4 + 3/4
2x - 20 = 4x + 3
2x - 4x = 3 + 20
-2x = 23
x = -23/2

h) -x/3 - x/2 = 2/3  (mmc: 6)

-2x/6 -3x/6 = 2.2/6
-2x - 3x = 4
-5x = 4
x = -4/5

o) 2 + 3x/2 = x + 3/2  (mmc: 2)
2.2/2 + 3x = 2x/2 + 3
4 + 3x = 2x + 3
3x -2x = 3 - 4
x = -1