The difference of 13 and 6, multiplied by a number written as an algebra expression

The equation respenting the left table is

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

Evaluate the expression for the given value of the variable 2×(c2-5) for c=4