Question

2. Resolva as equações do 1º grau, calculando o valor de x.

a) 3(x + 3) - 1= 2

b) 3(x + 2)= 2(x - 7)

c) 3(x + 2)= 2(x + 3) + 6

d) 6x + 3(x + 1) - 7= 2(2x - 1) - 4(1 - x) ​

Answer 1

Resposta:

a) 3(x + 3) - 1= 2

$3x + 9 - 1 = 2 \\ 3x + 9 - 1 - 2 = 0 \\ 3x + 6 = 0 \\ 3x = - 6 \div (3) \\ x = - 2$

b) 3(x + 2)= 2(x - 7)

$3x + 6 = 2x - 14 \\ 3x + 6 - 2x + 14 = 0 \\ x + 20 = 0 \\ x = - 20$

c) 3(x + 2)= 2(x + 3) + 6

$3x + 6 = 2x + 6 + 6 \\ 3x + 6 - 2x - 6 - 6 = 0 \\ x - 6 = 0 \\ x = 6$

d) 6x + 3(x + 1) - 7= 2(2x - 1) - 4(1 - x)

$6x + 3x + 3 - 7 = 4x - 2 - 4 + 4x \\ 9x - 4 = 8x - 6 \\ 9x - 4 - 8x + 6 = 0 \\ x + 2 = 0 \\ x = - 2$