I think the question is
Find the value of c so that (x-5) is a factor of the polynomial

The other factor is going to be some quadratic. We can say a few things about its coefficients but let's start by saying in general it's



Equating respective coefficients,




so we get



Answer: -37
Check:

F(-4)=G(-4) because when the two lines cross over the f line is at the -4 and same with G
By measuring and knowing the wait of the ounces and height