5 * 5 matrix invert

how to write 5 * 5 matrix invert?
Is there any simple examples?
thank you!

So is this a maths question or a coding question?

maths:
http://www.google.com/search?q=matrix+inversion

code:
int matrix[5][5];

i know the math
but don't know how to write the codes

Not all matrices are invertible. One simple test to see if a matrix is invertible is by using the determinant. If the determinant is nonzero, it is invertible.

I don't know how to code this, but I can give information on how an inverse is found....

If you take your matrix and perform a series of operations on it to transform it to the identity matrix and then perform the exact same operations in the exact same order on the identity matrix, the matrix formed will be the inverse of the original.