Problem
Find the determinant of the 2x2 matrix \( A = \begin{bmatrix} 3 & 4 \\ 2 & 5 \end{bmatrix} \).
Solution
Step 1 ：The determinant of a 2x2 matrix \( A = \begin{bmatrix} a & b \\ c & d \end{bmatrix} \) is given by the formula \( ad - bc \).
Step 2 ：Substitute the given values into the formula, we get \( (3)(5) - (2)(4) \).
Step 3 ：Simplify the expression to get the determinant.
