Question

Resolva as equações:
a)8x-12=28 *
b)3x-15=x+27 *
c)3x+15=x+27 *
d)2x-23+2x=57-x *
e)5x+40-16=4x+44 *
f)18-2x+14=-4x+10 *
g)-5x+35+2x=-2-4x+12 *
h)4x+4-10x+15=43 *
i)2x+3x+9=48-8x *
j)7x-7-2x+10=x-5 *

Answer 1

a) 8x - 12 = 28

8x = 28 + 12

8x = 40

x = 40/8

x = 5

b) 3x - 15 = x + 27

3x - x = 27 + 15

2x = 42

x = 42/2

x = 21

c) 3x + 15 = x + 27

3x - x = 27 - 15

2x = 12

x = 12/2

x = 6

d) 2x - 23 + 2x = 57 - x

2x + 2x + x = 57 + 23

6x = 80

x = 80/6

x = 13,3

e) 5x + 40 - 16 = 4x + 44

5x - 4x = 44 - 40 + 16

x = 20

f) 18 - 2x + 14 = -4x + 10

18 + 14 - 10 = -4x + 2x

22 = -2x

-22/2 = x

- 11 = x

g) -5x + 35 + 2x = -2 - 4x + 12

-5x + 2x + 4x = -2 + 12 - 35

-5x + 6x = -25

x = -25

h) 4x + 4 - 10x + 15 = 43

4x - 10x = 43 - 4 - 15

-6x = 24

x = -24/6

x = -4

i) 2x + 3x + 9 = 48 - 8x

2x + 3x + 8x = 48 - 9

13x = 39

x = 39/13

x = 3

j) 7x - 7 - 2x + 10 = x - 5

7x - 2x + x = -5 + 7 - 10

6x = -8

x = -8/6

x = - 4/3