Question

(FEI-SP) O conjunto solucao da equacao 2/3/4 - 2/3/4 = - 5/x e: A) S={1} B)S={2} C)S={3} D)S={4}

Answer 1

Explicação passo-a-passo:

$\dfrac{\frac{2}{3}}{4}-\dfrac{2}{\frac{3}{4}}=-\dfrac{5}{x}$

$\dfrac{2}{3}\cdot\dfrac{1}{4}-\dfrac{2}{1}\cdot\dfrac{4}{3}=-\dfrac{5}{x}$

$\sf \dfrac{2}{12}-\dfrac{8}{3}=-\dfrac{5}{x}$

$\sf \dfrac{1}{6}-\dfrac{8}{3}=-\dfrac{5}{x}$

$\sf \dfrac{1-16}{6}=-\dfrac{5}{x}$

$\sf \dfrac{-15}{6}=-\dfrac{5}{x}$

$\sf \dfrac{-5}{2}=\dfrac{-5}{x}$

$\sf x=2$

$\sf S=\{2\}$

Letra B

Answer 2

Oie, Td Bom?!

>>> Resposta: Opção B.

$\frac{ \frac{2}{3} }{4} - \frac{2}{ \frac{3}{4} } = - \frac{5}{x}$

$\frac{1}{6} - \frac{8}{3} = - \frac{5}{x}$

$\frac{ 1- 16}{6} = - \frac{5}{x}$

$\frac{ - 15}{6} = - \frac{5}{x}$

$- \frac{15}{6} \div 3 = - \frac{5}{x}$

$- \frac{5}{2} = - \frac{5}{x}$

$- 1 \: . \: ( - \frac{5}{2} ) = - 1 \: . \: ( - \frac{5}{x} )$

$\frac{5}{2} = \frac{5}{x}$

• Multiplicação-cruzada:

$\frac{5x}{2} = 5$

$5x = 5 \: . \: 2$

$5x = 10$

$x = \frac{10}{5}$

$x = 2$

$S = \left \{ 2\right \}$

Att. Makaveli1996