# I am confused on how you would this problem?

This is a minor matrix problem and I have not idea how you go about doing this problem.I had look at my textbook and the glorious khan academy. I think it how khan academy showed where go though many possibles which was way to confusing to explain.So can some point me to the right direction?(Problem is in the Image)

### 2 Answers

- anonymousLv 71 month ago
I can't draw the brackets around matrices on here, but I thought it was the following:

.1 .. -7 ... 2

.4 ... 8 .. -9

-8 ... 7 ... 3

M₁₃ is the determinant of the minor matrix made by removing row 1 and column 3 from the original matrix. In this case, that minor matrix is

.4 .. 8

-8 .. 7

which has determinant

(4 * 7) - (8 * -8)

= 28 - (-64)

= 92

M₁₃ = 92

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- oldprofLv 71 month ago
M1,3 = 2*(24-(-9*7)) = 174 ANS If Mx,y is assumed.

I'm not familiar with the notation M1,3. Anyway it appears you left the 2, which is at (1,3) off the minor calculation.

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- AlanLv 71 month agoReport
Yes, in finding the determinint, you multiply by 2*(-1)^(r+c) = 2*(-1)^(3+1) = 2

but the definition of minor doesn't include this part. C_1,3 = 2*(-1)^(r+c)* M_1_3

where C = cofactor and M = minor - Login to reply the answers