Question

1) Resolva as equações:
a) 4x + 8 = 3x - 5
b) 3a - 4 = a + 2
c) 9y - 11 = -2
d) 5x - 1 = 8x + 5
e) 2x - 3 = 15

Answer 1

Resposta:

a) 4x + 8 = 3x - 5

$4x + 8 - 3x = 5 \\ x = 5 - 8 \\ x = - 3$

b) 3a - 4 = a + 2

$3a - 4 - a = 2 \\ 2a = 2 + 4 \\ 2a = 6 \\ a = \frac{6}{2} \\ a = 3$

c) 9y - 11 = -2

$9y = - 2 + 11 \\ 9y = 9 \\ y = 1$

d) 5x - 1 = 8x + 5

$5x - 1 - 8x = 5 \\ - 3x = 5 + 1 \\ - 3x = 6 \times ( - 1) \\ 3x = - 6 \\ x = - \frac{6}{3} \\ x = - 2$

e) 2x - 3 = 15

$2x = 15 + 3 \\ 2x = 18 \\ x = \frac{18}{2} \\ x = 9$