SOLUTION: Please help! 1) Find the inverse of the matrix [ -9 5 6 -3 ] 2) solve the following equation | 0 0 -1 | | 3 x 0

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Question 1017168: Please help! 1) Find the inverse of the matrix [ -9 5 6 -3 ]
2) solve the following equation
| 0 0 -1 |
| 3 x 0 | =x^2
| 2 0 3 |

Answer by ikleyn(52834) About Me  (Show Source):
You can put this solution on YOUR website!
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Please help! 1) Find the inverse of the matrix [ -9 5 6 -3 ]
2) solve the following equation
| 0 0 -1 |
| 3 x 0 | =x^2
| 2 0 3 |
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Co-factor the determinant along the first row.
(see the lesson Co-factoring the determinant of a 3x3 matrix in this site to learn how to do it).


Then the determinant is (-1)*det%28matrix%282%2C2%2C+3%2C+x%2C+2%2C+0%29%29 = (-1)*(-2x) = 2x.

So your equation is 

x = x%5E2,

and its roots are  x=0  and/or  x = 1.

Regarding your first question, do you know that only square matrices have the inverse?