Question

5) Resolva as equações a seguir.
a) 3.(2x - 5) - 2.(x + 4) = 6x + 7
b) 4x -12 + 5.( - 2x - 5) = - 4.(3x + 6)
c) x + x/2 + 3x/4 = 18​

Answer 1

a) 3.(2x - 5) - 2.(x + 4) = 6x + 7

6x - 15 - 2x + 8 = 6x + 7

-15 - 2x - 8 = 7

-23 - 2x = 7

-2x = 7 + 23

-2x = 30

x = 30/-2

x = -15

b) 4x -12 + 5.( - 2x - 5) = - 4.(3x + 6)

4x - 12 - 10x - 25 = -12x - 24

-6x - 37 = -12x - 24

-6x + 12x = -24 + 37

6x = 13

x = 13/6

c) x + x/2 + 3x/4 = 18​

4x + 2x + 3x = 72

9x = 72

x = 72/9

x = 8