Question

Resolva as equações do 1 grau:

a) 7x + 5 = 68 – 2x
b) –2 · (x – 3) = 18
c) x+5 : 2 = 8+2x : 5
d) 5 · (y – 3) = 2y + 3

Answer 1

Resposta:

a) x = 7

b) x = -6

c) x = -9

d) y = 6

Explicação passo-a-passo:

$7x + 5 = 68 - 2x \\ 7x + 2x = 68 - 5 \\ 9x = 63 \\ x = \frac{63}{9} \\ x = 7$

$- 2.(x - 3) = 18 \\ - 2x + 6 = 18 \\ - 2x = 18 - 6 \\ - 2x = 12 \\ x = \frac{12}{ - 2} \\ x = - 6$

$\frac{x + 5}{2} = \frac{8 + 2x}{5} \\ 5.(x + 5) = 2.(8 + 2x) \\ 5x + 25 = 16 + 4x \\ 5x - 4x = 16 - 25 \\ x = - 9$

$5.(y - 3) = 2y + 3 \\ 5y - 15 = 2y + 3 \\ 5y - 2y = 3 + 15 \\ 3y = 18 \\ y = \frac{18}{3} \\ y = 6$