Hi, matrix A=

-7 18

-3 8

I need to find $\displaystyle A^2$ using $\displaystyle A^2=(P)(D^2)(P^-1)$

P=

2 3

1 1

P^-1 =

-1 3

1 -2

D^2 =

4 0

0 1

My problem is how do I multiply out PD^2P^-1 correctly? its doesnt seem to give A^2 as the answer?

Thanks