Question

determine o valor de x nas proporções

Answer 1

a) 3 × ( x + 10 ) = 2 × ( x - 6 )
3x + 30 = 2x - 12
3x - 2x = - 12 - 30
x = - 42

b) 18 × ( 2x + 2 ) = 6 × ( 3x - 2 )
36x + 36 = 18x - 12
36x - 18x = - 12 - 36
18x = - 48
x = - 48 \ 18
x = 8 \ 3 Obs: simplifiquei por 3 e depois por 2.

c) 4 × ( x + 8 ) = 4 × 2x
4x + 32 = 8x
4x - 8x = - 32
- 4x = - 32
x = - 32 \ - 4
x = 8

d) 1 × ( x + 4 ) = 7 × ( x - 2 )
x + 4 = 7x - 14
x - 7x = - 14 - 4
- 6x = - 18
x = - 18 \ - 6
x = 3

e) 10 × ( x + 2 ) = 5 × ( x - 2 )
10x + 20 = 5x - 10
10x - 5x = - 10 - 20
5x = - 30
x = - 30 \ 5
x = - 6

f) 7 × ( 5x + 3 ) = 5 × 3x
35x + 21 = 15x
35x - 15x = - 21
20x = - 21
x = - 21 \ 20