Question

AJUDAAAA É PRA AMANHÃ SCRR​

Answer 1

Explicação passo-a-passo:

A)

$\dfrac{x}{3} = \dfrac{8}{12}$

$12x = 3 \times 8$

$12x = 24$

$x = \dfrac{24}{12}$

x=>2

B)

$\dfrac{2.1}{7} = \dfrac{x}{10}$

$0.3 = \dfrac{x}{10}$

$0.3 \times 10 = x$

$3 = x$

x=>3

C)

$\dfrac{2}{15} = \dfrac{3}{2x}$

$15 \times 3 = 2 \times 2x$

$45 = 4x$

$4x = 45$

x=>45/4

D)

$\dfrac{x + 6}{x - 6} = \dfrac{2}{3}$

$3(x + 6) = 2(x - 6)$

$3x + 18 = 2x - 12$

$3x - 2x = - 12 - 18$

x=>-30

E)

$\dfrac{1}{5} = \dfrac{x - 6}{x + 1.5}$

$\dfrac{1}{5} = \dfrac{x - 6}{x + \dfrac{15 {}^{ \div 5} }{10 {}^{ \div 5} } }$

$\dfrac{1}{5} = \dfrac{x - 6}{x + \dfrac{3}{2} }$

$\dfrac{1}{5} = \dfrac{x - 6}{ \dfrac{2x + 3}{2} }$

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

$\dfrac{1}{5} = \dfrac{2x - 12}{2x + 3}$

$2x + 3 = 5(2x - 12)$

$2x + 3 = 10x - 60$

$2x - 10x = - 60 - 3$

$- 8x = - 63( - 1)$

$8x = 63$

x=>63/8

F)

$\dfrac{ \dfrac{3}{4} }{ \dfrac{1}{3} } = \dfrac{ \dfrac{1}{2} }{x}$

$\dfrac{3}{4} \times \dfrac{3}{1} = \dfrac{1}{2} \times \dfrac{1}{x}$

$\dfrac{9}{4} = \dfrac{1}{2x}$

$9 \times 2x = 4 \times 1$

$18x = 4$

$x = \dfrac{4 {}^{ \div 2} }{18 {}^{ \div 2} }$

x=>2/9