Question

Determine o Valor de x:​

Answer 1

Resposta:

primeira:

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

$2x = 3 \times 4\\2x = 12\\\\x = \dfrac{12}{2} \\\\x = 2$

Segunda:

$\dfrac{4}{12} = \dfrac{x}{21}$

$12x = 4 \times 21\\12x = 84\\\\x= \dfrac{84}{12} \\\\x = 7$

Terceira:

$\dfrac{x}{4} = \dfrac{9}{18} \\18x = 4 \times 9\\18x = 36\\\\x = \dfrac{36}{18} \\\\x = 2$

Quarta:

$\dfrac{10}{15} = \dfrac{3x + 1}{5x -\, 2} \\\\ 10 \times (5x -\,2) = 15 \times (3x + 1)\\50x -\, 20 = 45x + 15\\50x -\ 45x = 15 + 20\\5x = 35\\\\x = \dfrac{35}{5} \\\\x = 7$

Explicação passo-a-passo: