4) There are three kinds of boxes. The first kind costs $2 each, the second, $3 each, the third, $2 each; the first weighs 1 lb. each, the second, 3 lb. each, the third, 3 lb. each. The first has a volume of 1 cubic feet, the second, 4 cubic feet, the third, 5 cubic feet. If the total cost of the boxes is $18, the total weight of the boxes is 19 pounds, and the total volume of the boxes is 27 cubic feet, how many of each of the three kinds of boxes are there? 2) Use Gauss-Jordan to solve 2x + a. 3y = 19 2y = 20 5x + 2x + 3y + 2z = 18 + 3y + 3z = 19 + 4y + + 5z = 27 b. x x