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If [1324][35−13]=[m142n]\begin{bmatrix} 1 & 3 \\ 2 & 4 \end{bmatrix} \begin{bmatrix} 3 & 5 \\ -1 & 3 \end{bmatrix} = \begin{bmatrix} m & 14 \\ 2 & n \end{bmatrix}, then m+nm + n is equal to

Solution

✅ Correct Option: 2

To multiply two 2×2 matrices, each entry in the result is found by multiplying corresponding elements from a row of the first matrix with a column of the second matrix, then summing.


For mm (position row 1, column 1):

Take row 1 from the first matrix: [1,3][1, 3]

Take column 1 from the second matrix: [3,−1][3, -1]

m=(1×3)+(3×−1)m = (1 \times 3) + (3 \times -1)

m=3+(−3)m = 3 + (-3)

m=0m = 0


For nn (position row 2, column 2):

Take row 2 from the first matrix: [2,4][2, 4]

Take column 2 from the second matrix: [5,3][5, 3]

n=(2×5)+(4×3)n = (2 \times 5) + (4 \times 3)

n=10+12n = 10 + 12

n=22n = 22


Therefore:

m+n=0+22m + n = 0 + 22

m+n=22m + n = 22

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