Find the number whose sum is 50 if the first number is 3 times the difference between the second and the third and the second number is two more than twice the third. solve the problem using matrices

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