Question

{x/8+y/12=-1
{6x+y=-120

Answer 1

$\left \{{{x/8+y/12=-1}\atop{6x+y=-120}}\right. \\ \left \{{{x/8+y/12=-1\big|*24}\atop{6x+y=-120}}\right. \\ \left \{{{3x+2y=-24\big|*2}\atop{6x+y=-120}}\right.$

$\left\{ {{6x+4y=-48}\atop{6x+y=-120}}\right.$
$-\left \{{{6x+4y=-48}\atop{6x+y=-120}}\right.$
$\;4y-y=-48-(-120)\\ \;3y=72$
$y=24\\ \left \{{{x/8+y/12=-1}\atop{y=24}}\right. \\ \left \{{{x/8+2=-1}\atop{y=24}}\right. \\ \left \{{{x/8=-3}\atop{y=24}}\right. \\ \left \{{{x=-24}\atop{y=24}}\right. \\ ANSWER:(-24;24)$