Determinants and Cramer's Rule
1 Evaluate a Second-Order Determinant
-$\left| \begin{array} { c c } \frac { 1 } { 3 } & \frac { 1 } { 6 } \ - \frac { 4 } { 7 } & \frac { 3 } { 4 } \end{array} \right|$
A) $\frac { 29 } { 84 }$
B) $\frac { 13 } { 84 }$
C) $\frac { 1 } { 72 }$
D) $- \frac { 53 } { 168 }$

Question

Quizplus · Accepted Answer

The determinant of a 2x2 matrix $\left| \begin{array} { c c } a & b \ c & d \end{array} \right|$ is calculated as $ad - bc$. For this matrix, it is $\frac{1}{3} \cdot \frac{3}{4} - \frac{1}{6} \cdot -\frac{4}{7} = \frac{1}{4} + \frac{4}{42} = \frac{21}{84} + \frac{8}{84} = \frac{29}{84}$.

Determinants and Cramer's Rule 1 Evaluate a Second-Order Determinant - ∣1316−4734∣\left| \begin{array} { c c } \frac { 1 } { 3 } & \frac { 1 } { 6 } \\ - \frac { 4 } { 7 } & \frac { 3 } { 4 } \end{array} \right|​31​−74​​61​43​​​

Determinants and Cramer's Rule
1 Evaluate a Second-Order Determinant
- $\left| \begin{array} { c c } \frac { 1 } { 3 } & \frac { 1 } { 6 } \\ - \frac { 4 } { 7 } & \frac { 3 } { 4 } \end{array} \right|$