Matrix+equations+and+inverses+(how+do+we+tell+when+two+matrices+are+inverses?)+Set+6

Give an example of a system of 4 equations with 4 unknowns whose solution is (2, 1, 0, 3). Ask a classmate to solve the system of equations by setting up a matrix equation and show how to solve using inverses.

Give two pairs of matrices -- one pair that are inverses and one pair that is not. Ask a classmate to determine which pair of matrices are inverses, and demonstrate why. This classmate is NOT allowed to use a calculator!!

Which pair is a pair of inverses and why? [5 7] and [9 2/3 9] [8 1/2] [11/8 6 9] [1 4]

or

[5 4] and [1/3 -2/3 [1 2] [-1/6 5/6]