SOLUTION: How do you find the value of |A| in this problem, A = [ -1 4(row 1) 9 -3(row 2)]???

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Question 1053504: How do you find the value of |A| in this problem, A = [ -1 4(row 1) 9 -3(row 2)]???
Found 2 solutions by Fombitz, ikleyn:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
For a 2x2 matrix, A,
A=%28matrix%282%2C2%2C%0D%0Aa%2Cb%2C%0D%0Ac%2Cd%29%29
abs%28A%29=a%2Ad-b%2Ac

Answer by ikleyn(52848) About Me  (Show Source):
You can put this solution on YOUR website!
.
On determinants for 2x2- matrices see the lesson
    - Determinant of a 2x2-matrix
in this site.