The U-Box-It store carries boxes in four sizes. The tables below show the four sizes of storage boxes the store sells and the revenues earned in the summer quarter. For how much did each type of box sell?
I put the equations
12A + 35B + 20C + 5D = 425.25
18A + 42B + 33C + 21D = 732
20A + 28B + 24C + 10D = 500
In matrix and did rref(A) on my calculator, I got the equations
A - 55/54D = -559/108
B - 131/189D = -1009/756
C - 56/27D = 721/27
and now I am stuck and do not know how to solve for the equations in order to get a value for each of the letters A, B, C, D. Any help would be much appreciated.