I need help with geometry

The product of two negative rational numbers is always zero sometimes zero never zero

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

Factor the expression using the gcf. the expression 21m−49n factored using the gcf