Question

resolva as equações

a)3x=15
b)2x=14
c)4x-12
d)7x=-21
e)3x=13
f)4x=-9
g)25x=0
h)35x=-105
i)4x=1
j)36x=12
k)21=3x
l)84=6x

Answer 1

a) 3x = 15
x = 15/3
x = 5

b) 2x = 14
x = 14/2
x = 7

c) 4x - 12 = 0
4x = 12
x = 12/4
x = 3

d) 7x = -21
x = - 21/7
x = - 3

e) 3x = 13
x = 13/3

f) 4x = - 9
x = - 9/4

g) 25x = 0
x = 0

h) 35x = - 105
x = - 105/35
x = - 3

i) 4x = 1
x = 1/4

j) 36x = 12
x = 12/36
x = 1/3

k) 21 = 3x
3x = 21
x = 21/3
x = 7

L) 84 = 6x
6x = 84
x = 84/6
x = 14

Answer 2

a) 3x = 15
x = 15
       3
x = 5

b) 2x = 14
x = 14
       2
x = 7

c) 4x - 12 = 0
4x = 12
x = 12
       4
x = 3

d) 7x = - 21
x = - 21
        7
x = - 3

e) 3x = 13
x = 13
       3

f) 4x = - 9
x = - 9
       4

g) 25x = 0
x =  0 
      25
x = 0

h) 35x = - 105
x = - 105
        35
x = - 3

i) 4x = 1
x = 1
      4

j) 36x = 12
x = 12 : 2 =  6 : 2 = 3 : 3 = 1
      36 : 2   18 : 2    9 : 3    3

k) 21 = 3x
- 3x = - 21 .(- 1)
3x = 21
x = 21
       3
x = 7

l) 84 = 6x
- 6x = - 84 .(- 1)
6x = 84
x = 84
       6
x = 14