# Matrix eq

1. Dec 23, 2008

### fazal

Given that A^-1 , B^-1 and C^-1 exist, solve the following equations for X:

a)AX=C
b)AXB=C
c)BXA=C+B
d)XABC=D

plse help....

2. Dec 23, 2008

### HallsofIvy

Staff Emeritus
a) Multiply both sides of the equation on the left by A-1:
A-1AX= X= A-1C.
b) Multiply both sides of the equation on the left by A-1 and on the right by B-1:
A-1AXBB-1= X= A-1CB-1

Can you try c and d now?

3. Dec 23, 2008

### fazal

so
c) X=(C+B)A^-1B^-1

d)X=B^-1C^-1D

plse check thks

4. Dec 23, 2008

### NoMoreExams

c)BXA=C+B

Therefore XA = B^(-1)(C+B) therefore X = B^(-1)(C+B)A^(-1)

Remember matrix multiplication is NOT commutative.

Do the same steps for d), note ORDER MATTERS

Last edited: Dec 23, 2008