Finding the inverse of a matrix, please help 10pts!

[2 4 2]
[2 5 2]
[0 2 -1]

I've gotten up to this bit:

[1 0 5 | -1/2 -2 0]
[0 1 -2| 1/2 1 0]
[0 0 9| -3 -6 3]

I can't figure out how to get a 1 on the bottom right corner or the remaining two 0's. Help would be appreciated!

Just divide every term in Row three by 9. Then the 3rd row will look like:

[0 0 1| -1/3 -2/3 1/3]

Now you can work from the bottom up to get rid of the -2 and 5 above, and you're done.

A^-1 = (Adj. A)/ Det. A

Find Adj. A and |A| and calculate A^-1.