Question

решите уравнение х-1/2=3/4х; 1 4/5у=у+4; 3/4у-2/3=7/12у;

Answer 1

1) $x- frac{1}{2}= frac{3}{4}x$
$x- frac{3}{4}x= frac{1}{2}$
$frac{1}{4}x= frac{1}{2}$
$x= frac{1*4}{2*1}$
$x=2$
2) $frac{4}{5}y=y+4$
$frac{4}{5}y-y=4$
$-frac{1}{5}y=4$
$y= frac{4*(-5)}{1}$
$y=-20$
3) $frac{3}{4}y - frac{2}{3}= frac{7}{12}y$
$frac{3}{4}y- frac{7}{12}y= frac{2}{3}$
$frac{9-7}{12}y= frac{2}{3}$
$frac{2}{12}y= frac{2}{3}$
$y= frac{2*12}{3*2}$
$y=4$