Question 1030734
I'm assuming you mean less than or equal to and greater than or equal to in order to include the vertices.
({{{-4}}},{{{1}}})
({{{-4}}},{{{6}}})
({{{-2}}},{{{1}}})
({{{-2}}},{{{1}}})
Now check the function at each point,
({{{-4}}},{{{1}}}): {{{C=5(-4)+4(1)=-20+4=-16}}}
Do the same for the remaining 3 points.