Question

a) 5x+4 =  4  
    10         2

b)  5   = 30 
   x+4    54

c) 1    =  x-6 
    7        49

d) 0,9 =  -18  
     x       27

Conta Por favor?

Answer 1

$A) \frac{5x+4}{10} = \frac{4}{2}$
$2*(5x + 4)=10*4$
$10x+8=40$
$10x=40-8$
$10x=32$
$x= \frac{32}{10}$
$x=3.2$

$B) \frac{5}{x+4} =\frac{30}{54}$
$54*5=30(x+4)$
$30x +120 = 270$
$30x=270-120$
$30*=150$
$x= \frac{150}{30}$
$x=5$

$C) \frac{1}{7}= \frac{x-6}{49}$
$49=7(x-6)$
$49=7x-42$
$7x=49+42$
$7x=91$
$x= \frac{91}{7}$
$x=13$

$D) \frac{0.9}{x} = \frac{-18}{27}$
$27* \frac{9}{10} =-18x$
$\frac{243}{10}=-18x (*-1)$
$18x=-24.3$
$x=\frac{-24.3}{18}$
$x=-1.35$