Question

решите уравнение (1400+x)/(70+30)=3/60

Answer 1

$\frac{(1400+x)}{(70+30)}= \frac{3}{60}$
$\frac{1400+x}{100}= \frac{1}{20}$
$20(1400+x)=100$
$1400+x=5$
$x=5-1400$
$x=-1395$