Question

Resolva as equações
A)2x + 5 = 8

B)4x -10 = 10 +2x

C)2( 6x + 3) = 20

D)-3( 5x -2) = -2( 2x + 4)

E)7 (4x + 8) +15 = -2(x + 2 ) + 45

Answer 1

a)2x + 5 = 8

2x = 8 - 5

2x = 3

x = 3/2

b)4x - 10 = 10 + 2x

4x - 2x = 10 + 10

2x = 20

x = 20/2

x = 10

c) 2(6x + 3) = 20

12x + 6 = 20

12x = 20 - 6

12x = 14

x = 14/12

x = 7/6 (simplificado)

d) -3(5x - 2) = -2(2x + 4)

-15x + 6 = -4x - 8

-15x + 4x = -8 - 6

-11x = -14 .(-1)--> multiplica por -1 p/ficar positivo

x = 14/11

e)7(4x + 8) + 15 = -2(x + 2) + 45

28x + 56 + 15 = -2x - 4 + 45

28x + 2x = -4 + 45 - 56 - 15

30x = 8

X = 8/30

x = 4/15 (simplificado)