Question 1015054
{{{x}}} is the distance along the floor away from the catapult, {{{y}}} is the height from the floor.
So find x when y=0.
{{{-2x^2+10x+12=0}}}
{{{x^2-5x-6=0}}}
You can factor,
{{{(x-6)(x+1)=0}}}
Two solutions but in this case only positive solutions make sense.
{{{x-6=0}}}
{{{x=6}}}