Posted by **Katherine** on Tuesday, November 18, 2008 at 6:14pm.

find the values of a and b given that matrix A=

[a -4 -6]

[-8 5 7]

[-5 3 4]

is the inverse of matrix B =

[1 2 -2]

[3 b 1]

[-1 1 -3]

It would really help if you showed how you did it.

Thanks a lot!

- Math -
**Reiny**, Tuesday, November 18, 2008 at 8:23pm
I trust you know how to multiply two matrices

and I trust that you know that if you multiply any matrix by its inverse you get the identity matrix, namely

1 0 0

0 1 0

0 0 1

so using the first row of matrix A and the first column of matrix B you get

a - 12 + 6 = 1

a = 7

then second row of A by second column of B gives us

-16 + 5b + 7 = 1

b = 2

## Answer this Question

## Related Questions

- MATHS----Matrix - For a given square matrix A the predicted values of matrix B ...
- math - This is a matrix question. R is the matrix (3r 1) (s 2s) 1. State, in ...
- math - This is a matrix question. R is the matrix (3r 1) (s 2s) 1. State, in ...
- Math - Hi! I need help with these two questions. Thanks! :) 1.) Can we multiply ...
- Calc - A video games shop is analyzing its sales performance using matrices. ...
- Math - Fine the size of the following matrix and its additive inverse matrix. ...
- Algebra II (Matrices) - My book doesn't solve it like a linear equation, they ...
- Math - Let A, B, and 0 be 2x2 matrices. Assuming that A is invertible, find a ...
- algebra - When i have a matrix 4 X 4 and i have to multiply it by a 4 X 3 i know...
- math,algebra II - I have to work with these types of problems dealing with ...

More Related Questions