Question

{8х+5у=20, {1.6х+2у=0

Answer 1

$x= \frac{5}{2}- \frac{y}{8} 1,6x+2y=0$

$1,6*( \frac{5}{2} - \frac{y}{8} )+2y=0$

$1,6= \frac{16}{10} = \frac{8}{5}$

$\frac{8}{5}*( \frac{5}{2}- \frac{y}{8} ) +2y=0$

$4- \frac{1}{5}y+2y=0$

$4+ \frac{9}{5}y=0$

$4*5+ \frac{9}{5} y*5=0$

$20+9y=0 \\20+9y=0$

$9y=-20$

$y= - \frac{20}{9}$

$1,6x+2*(- \frac{20}{9} )=0$

$x= \frac{25}{9}$