Question

Resolva as equações do 1ograu abaixo: a) 2. ( 6 – x ) = - 2x + 12 b) 6( x + 1) – 2(5 – 2x) = 4x – x + 3 c) 2( x + 3) = 4( x – 1) d) 5 – 3( x + 1) = 2 + x e) 8( x – 1) – 2 + x = -3( x + 4) – 5 + x f) 7x – 3( x – 2) = 3( x + 4) g) 2( 1 – x) + 1 = 3( x – 3) – 2x h) 5( x + 1) – 3 ( 2x + 1) = 4( 5 – x)

Answer 1

Resposta:

a) 2. ( 6 – x ) = - 2x + 12

$12 - 2x = - 2x + 12 \\ 12 - 2x + 2x - 12 = 0 \\ 0$

b) 6( x + 1) – 2(5 – 2x) = 4x – x + 3

$6x + 6 - 10 + 4x = 4x - x + 3 \\ 10x - 4 = 3x + 3 \\ 10x - 4 - x - 3 = 0 \\ 9x - 7 = 0 \\ 9x = 7 \\ \\ x = \frac{7}{9}$

c) 2( x + 3) = 4( x – 1)

$2x + 6 = 4x - 4 \\ 2x + 6 - 4x + 4 = 0 \\ - 2x + 10 = 0 \\ - 2x = - 10 \times \times ( - 1) \\ 2x = 10 \div (2) \\ x = 5$

d) 5 – 3( x + 1) = 2 + x

$5 - 3x - 3 = 2 + x \\ 2 - 3x = 2 + x \\ 2 - 3x - 2 - x = 0 \\ - 4x = 0 \times ( - 1) \\ 4x = 0 \\ x = 0$

e) 8( x – 1) – 2 + x = -3( x + 4) – 5 + x

$8x - 8 - 2 + x = - 3x - 12 \\ 9x - 10 = - 3x - 12 \\ 9x - 10 + 3x + 12 = 0 \\ 12x + 2 = 0 \\ 12x = - 2 \div (2) \\ 6x = - 1 \\ \\ x = - \frac{1}{6}$

f) 7x – 3( x – 2) = 3( x + 4)

$7x - 3x + 6 = 3x + 12 \\ 4x + 6 = 3x + 12 \\ 4x + 6 - 3x - 12 = 0 \\ x - 6 = 0 \\ x = 6$

g) 2( 1 – x) + 1 = 3( x – 3) – 2x

$2 - 2x + 1 = 3x - 9x - 2x \\ 3 - 2x = 3x - 11x \\ 3 - 2x - 3x + 11x = 0 \\ 3 + 6x = 0 \\ 6x = - 3 \div (3) \\ 2x = - 1 \\ \\ x = - \frac{1}{2}$

h) 5( x + 1) – 3 ( 2x + 1) = 4( 5 – x)

$5x + 5 - 6x - 3 = 20 - 4x \\ - x + 2 = 20 - 4x \\ - x + 2 - 20 + 4x = 0 \\ 3x - 18 = 0 \\ 3x = 18 \div (3) \\ x = 6$