SOLUTION: Evaluate the determinate |-9,-7| |4,5|

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Question 636097: Evaluate the determinate
|-9,-7|
|4,5|
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Finding the Determinant of a 2x2 Matrix

If you have the general 2x2 matrix:

%28matrix%282%2C2%2Ca%2Cb%2Cc%2Cd%29%29

the determinant is: D=a%2Ad-c%2Ab

So this means that

abs%28matrix%282%2C2%2Ca%2Cb%2Cc%2Cd%29%29=a%2Ad-c%2Ab

Note: the vertical bars denote a determinant.


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So in this case the determinant of %28matrix%282%2C2%2C-9%2C-7%2C4%2C5%29%29 is:


abs%28matrix%282%2C2%2C-9%2C-7%2C4%2C5%29%29=%28-9%29%285%29-%284%29%28-7%29=-45--28=-17


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Answer:

So abs%28matrix%282%2C2%2C-9%2C-7%2C4%2C5%29%29=-17 which means that the determinant of the matrix %28matrix%282%2C2%2C-9%2C-7%2C4%2C5%29%29 is -17