Question

Resolva as equações de 1° grau a)
A)
$7(x - 1) - 2(x - 5) = x - 5$
B)
$3(2x + 3) - 4(x - 1) = 3$
C)
$2(3 - x) = 3(x - 4) + 15$
D)
$3(5 - x) - 3(1 - 2x) = 42$
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Answer 1

Explicação passo-a-passo:

a)

$7(x - 1) - 2(x - 5) = x - 5 \\ 7x - 7 - 2x + 10 = x - 5 \\ 5x - x + 3 = - 5 \\ 4x = - 5 - 3 \\ 4x = - 8 \\ x = \frac{ - 8}{4} \\ x = - 2$

b)

$3(2x + 3) - 4(x - 1) = 3 \\ 6x + 9 - 4x + 4 = 3 \\ 2x + 13 = 3 \\ 2x = 3 - 13 \\ 2x = - 10 \\ x = \frac{ - 10}{2} \\ x = - 5$

c)

$2(3 - x) = 3(x - 4) + 15 \\ - 2x + 6 = 3x - 12 + 15 \\ 3x + 2x = 6 - 3 \\ 5x = 3 \\ x = \frac{3}{5}$

d)

$3(5 - x) - 3(1 - 2x) = 42 \\ - 3x + 15 + 6x - 3 = 42 \\ 3x + 12 = 42 \\ 3x = 42 - 12 \\ 3x = 30 \\ x = \frac{30}{3} \\ x = 10$