Question

{3x-y=8
 {2x-y=7 scrieti va rog

Answer 1

{3x-y=8
{2x-y=7         ·(-1)⇒

{3x-y=8
{-2x+y=-7
3x-2x=8-7
x=1
din 2x-y=7⇒
y=2x-7
y=2·1-7
y=2-7
y=-5

Answer 2

$\left \{ {{3x-y=8} \ \ |(-1)\atop {2x-y=7}} \right. \\\\\\ \left \{ {{-3x+y=-8} \atop {2x-y=7}} \right. \\ ======== \\\\ -x/=-1 \\\\ \boxed{x=1} \\\\ 2x-y=7 \\\\ -y=7-2x \\\\ -y=7-2*1 \\\\ -y=7-2 \\\\ -y=5 \\\\ \boxed{y=-5}$