Evaluate.
-$$\left| \begin{array} { r r r }
7 & - 5 & 3 \
0 & 1 & 2 \
0 & 0 & - 9
\end{array} \right|$$
A) $- 73$
B) 53
C) $- 63$
D) 63

Question

Evaluate.
-$$\left| \begin{array} { r r r } 
7 & - 5 & 3 \
0 & 1 & 2 \
0 & 0 & - 9
\end{array} \right|$$
A) $- 73$
B) 53
C) $- 63$
D) 63

Quizplus · Accepted Answer

The determinant of a triangular matrix (all elements below or above the main diagonal are zero) is the product of its diagonal elements. For this matrix, the diagonal elements are 7, 1, and -9. Multiplying these gives $7 \times 1 \times (-9) = -63$.

Evaluate - ∣7−5301200−9∣\left| \begin{array} { r r r } 7 & - 5 & 3 \\0 & 1 & 2 \\0 & 0 & - 9\end{array} \right|​700​−510​32−9​​

Evaluate
- $\left| \begin{array} { r r r } 7 & - 5 & 3 \\0 & 1 & 2 \\0 & 0 & - 9\end{array} \right|$