Evaluate each determinant in Exercises 1–10. - 5 - 1 - 2 - 7

Question

Determinant of a 2x2 matrix with values -5, -1, -2, -7 for college algebra exercise.

Accepted Answer

Welcome back. I am so glad you're here. We are given this matrix. I'm going to copy it down and reading down the first column negative eight, negative nine. And the second column negative six. Negative four. And we are to evaluate the second order determinant. Will we recall from previous lessons on second order determinants that we're going to take the term in the upper left hand corner and multiply it by the term in the bottom right hand corner. So negative eight times negative four which would be a positive 32. And then we take the term in the bottom left hand corner and multiplied by the term in the upper right hand corner. So negative nine times negative six which is a positive 54. And then we are going to subtract those terms from each other. So starting with 32 the first one and then subtracting the 2nd 1, 54 32 minus 54 is negative 22 that is our determinant. We look at our answer choices and that matches with answer choice. D. Well done. We'll catch you on the next one.

Evaluate each determinant in Exercises 1–10. - 5 - 1 - 2 - 7

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