Pwease help!! i need help to put the answers in the box c:

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Which of the following is correct interpretation of the expression -4+13

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