Resposta:

A) x/4 - x/6 = 3

mmc(4,6)=12

3x-2x=36

x=36

B) 3x/4 - x/3 =5

mmc(4,3)=12

9x/12 - 4x/12 = 5

5x/12 = 5

x=12

C) x/5 - 1 = 9

x/5 = 9+1

x/5 = 10

x=50

D) x/3 - 5 =0

x/3 = 5

x=15

E) x/2 + 3x/5=6

mmc(2,5)=10

5x/10 + 6x/10 = 6

11x/10 = 6

x=60/11

F) x/5 + x/2 = 6

mmc(5,2)=10

2x/10 + 5x/10 = 6

7x/10 = 6

x=60/7

G) 5x - 10 = x + 1/2

5x-x=1/2+10

4x=21/2

x=21/8

H) 8x - 1/2 - 2x = 3

6x=7/2

x=7/12

I) 2 x-1/5 = x + 2/3

6x-1=15+10x

4x=16

x=4

J) 5x/2 = x + 2/3

5x/2 - x = 2/3

3x/2 = 2/3

x=4/9

K) x - 3/4 - 2x -1/5 = 5

-3x=5+5/4+1/5

-3x=126/20

x=-21/4

L) x - 1/2 + x -3/3 = 6

2x-1/2-1=6

2x=7.5

x=15/4