find A^-1 where A=(2 4 over 2 5)?

Question

not division

Answer 1

If you mean the matrix
|2...4|
|2...5|
It's inverse is
|5/2...-2|
|-1......1|

Doug

Answer 2

First find the determinant: (2)(5) - (2)(4) = 2.

Make the 5 and the top 2 switch places, then change the sign of the other two numbers and multiply that matrix by the inverse of the determinant.

(1/2) * 5 -4
.............-2 2



it's quite difficult to express matrices with this limited text input