Question

1) Nas figuras, a//b//c, calcule o valor de x.

URGENTEEE​

Answer 1

Resposta:

x=13

Explicação passo-a-passo:

x/12=19,5/18

18x=12.19,5

18x=234

x=234/18

x=13

Tente os outros.

Answer 2

Resposta:

$a)\frac{2x - 3}{x + 2} = \frac{5}{6} \\ 6.(2x - 3) = 5.(x + 2) \\ 12 \times - 18 = 5x + 10 \\ 12x - 5x = 10 + 18 \\ 7x = 28 \\ x = \frac{28}{7} \\ x = 4$

$b) \frac{x}{19.5} = \frac{12}{19} \\ 19x = 19.5 \times 12 \\ 19x = 243 \\ x = \frac{243}{19} \\ x = 12.31$

$c) \frac{x}{15} = \frac{10}{20} \\ 20x = 150 \\ x = \frac{150 \div 10}{20 \div 10} \\ x = \frac{15}{2} \\ x = 7.5$

$d)\frac{x}{x + 2} = \frac{9}{12} \\ 12x = 9.(x + 2) \\ 12x = 9x + 18 \\ 12x - 9x = 18 \\ 3x = 18 \\ x = \frac{18}{3} \\ x = 6$

$e)\frac{x + 5}{x} = \frac{x + 2}{x - 2} \\ x.(x + 2) = (x + 5).(x - 2) \\ {x}^{2} + 2x = {x }^{2} - 2x + 5x - 10 \\ ( {x}^{2} cancela) \\ 2x + 2x - 5x = - 10 \\ - x = - 10(multiplica \: tudo \: por \: - 1) \\ x = 10$

$f) \frac{x}{15} = \frac{x + 4}{20} \\ 20x = 15.( \times + 4) \\ 20x = 15x + 60 \\ 20x - 15x = 60 \\ 5x = 60 \\ x = \frac{60}{5} \\ x = 12$