If 5 people share 13 of a kilogram of potatoes equally?

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Two florida panthers were weighed. one weighs 6x+21 pounds and the two together weigh 14x+11 pounds how much does he other panther weigh alone