The perimeter of a rectangle is 36 inches. If its length is two times its width, find the dimensions (the length and the width). (Be sure to solve this problem with algebraic equations)

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