Question

Se 1/x+5 =4, o valor de 1/x+6 é ? (Justifique)

A) 1/5. B)1/4. C) 2/3 D) 4/5. E) 1

Answer 1

$\frac{1}{x+5} =4~~~~~~~~~~~~~~~~~~~~~~ \frac{1}{x+6} ?$

$\frac{1}{x+5} =4~~~~multiplica ~~cruzado$

$1=4x+20$
$4x = 1-20$
$4x=-19$
$\boxed {x= \frac{-19}{4} }$

$\frac{1}{ ~~\frac{-19}{4}+6 ~~~mmc=4}$

$\frac{1}{ \frac{-19+ 24}{4} } = \frac{1}{ \frac{5}{4} } = 1. \frac{4}{5} = \frac{4}{5}$ 

$Alternativa~~~~~D)$