The Peterson family takes their clothes to the local cleaners. The table below gives the number of coats, shirts, and dresses they had cleaned over the course of three months. They had no other items cleaned there.

Question

(January) 5 coats, 5 shirts, 6 dresses
(February) 1 coat, 8 shirts, 6 dresses
(March) 3 coats, 3 shirts, 2 dresses

If they spent
$77
at the cleaners in January,
$67
in February, and
$43
in March, what is the cost to have each item cleaned?

Cost to have a coat cleaned?
Cost to have a shirt cleaned?
Cost to have a dress cleaned?

Answer 1

Do you do matrix algebra on your calculator?

coats, shirts, dresses, cost
in augmented matrix form:
5,5,6,77
1,8,6,67
3,3,2,43

Now if you want to do it manually as a 3x3 set
5x+5y+6d=77 and so on, then solve it with pencil and paper. The augmented matrix is much faster..

Answer 2

deyh