Question

5- Determine e valor de x Para os casos abaixo A)8x-3=5 B) 3x = x+8 C) x-3=9 d) 4x-9=1-2x e) x+5=20-4 F) 9x-4 x + 10 = 7x-30​

Answer 1

Resposta:

a) x=1

b) x= 4

c) x= 12

d) x= 5/3

e) x= 11

f) x= 20

Explicação passo-a-passo:

a)$8x - 3 = 5 \\ 8x = 5 + 3 \\ 8x = 8 \\ x = \frac{8}{8} =x = 1$

b)

$3x = x + 8 \\ 3x - x = 8 \\ 2x = 8 \\ x = \frac{8}{2} = x = 4$

c)

$x - 3 = 9 \\ x = 9 + 3 \\ x = 12$

d)

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

e)

$x + 5 = 20 - 4 \\ x + 5 = 16 \\ x = 16 - 5 \\ x = 11$

f)

$9x - 4x + 10 = 7x - 30 \\ 5x + 10 = 7x - 30 \\ 5x - 7x = 30 - 10 \\ - 2 = - 40( - 1) \\ x = \frac{40}{2} = x = 20$