Question

Encontre o valor de x nas seguintes equações: A) 5x – 12 = 24 – 4x B) 18 – 2x = 54 – 5x C) 9.( x – 4 ) = 5.( x + 8 ) D) 15 + 3x + 25 = 40 – 2x + 65 E) 4.( x – 3 ) + 5.( x – 6 ) = 6. ( x + 9 )

Answer 1

Resposta:

A) 5x – 12 = 24 – 4x

$5x - 12 + 4x = 24 \\ 9x = 24 + 12 \\ 9x = 36 \\ x = \frac{36}{9} \\ x = 4$

B) 18 – 2x = 54 – 5x

$18 - 2x + 5x = 54 \\ 3x = 54 - 18 \\ 3x = 36 \\ x = \frac{36}{3} \\ x = 12$

C) 9.( x – 4 ) = 5.( x + 8 )

$9x - 36 = 5x + 40 \\ 9x - 5x - 36 = 40 \\ 4x = 40 + 36 \\ 4x = 76 \\ x = \frac{76}{4} \\ x = 19$

D) 15 + 3x + 25 = 40 – 2x + 65

$15 + 3x + 25 - 40 + 2x - 65 = 0 \\ 5x - 65 = 0 \\ 5x = 65 \\ x = \frac{65}{5} \\ x = 13$

E) 4.( x – 3 ) + 5.( x – 6 ) = 6. ( x + 9 )

$4x - 12 + 5x - 30 = 6x + 54 \\ 4x - 12 + 5x - 30 - 6x - 54 = 0 \\ 3x - 96 = 0 \\ 3x = 96 \\ x = \frac{96}{3} \\ x = 32$