SOLUTION: How do I find the inverse of [5 3] [7 9]? (That's supposed to be a matrix, I didn't know how to make one on here) So far I have gotten the determinan

Algebra ->  Matrices-and-determiminant -> SOLUTION: How do I find the inverse of [5 3] [7 9]? (That's supposed to be a matrix, I didn't know how to make one on here) So far I have gotten the determinan      Log On


   

Question 346215: How do I find the inverse of [5 3]
[7 9]? (That's supposed to be a matrix, I didn't know how to make one on here)
So far I have gotten the determinant of 21 but I don't remember what to do from there.
Thanks
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
[A]=%28matrix%282%2C2%2Ca%2Cb%2Cc%2Cd%29%29
D=det([A])
The inverse of a 2x2 matrix, [A], is given by,
[A]inv=%281%2FD%29%2A%28matrix%282%2C2%2Cd%2C-b%2C-c%2Ca%29%29