Find the determinant of the 3×3 matrix with rows (-2, 0, 3); (-1, 5, -1); (2, 1, -1).
Answer and explanation
Correct answer: A.
- Step 1: Expand along the first row: a(ei − fh) − b(di − fg) + c(dh − eg). Step 2. Evaluating gives -25. **Answer: . Why not the others:** is what you get if you get the overall sign wrong. is what you get if you use only the first cofactor term. does not fit.
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