document.write( "Question 375284: Please help me find the determinant of the matrix [-1 2
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Algebra.Com's Answer #266856 by jim_thompson5910(35256) $\"\"$ $\"About$

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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 $\"%28matrix%282%2C2%2C-1%2C2%2C1%2C3%29%29\"$ is:

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$\"abs%28matrix%282%2C2%2C-1%2C2%2C1%2C3%29%29=%28-1%29%283%29-%281%29%282%29=-3-2=-5\"$

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Answer:

So $\"abs%28matrix%282%2C2%2C-1%2C2%2C1%2C3%29%29=-5\"$ which means that the determinant of the matrix $\"%28matrix%282%2C2%2C-1%2C2%2C1%2C3%29%29\"$ is -5

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