Test Index

WAEC Further Mathematics 2024 Paper

Question : 27

Total: 40

\begin{pmatrix} 6 & 4 \\ 7 & 5 \end{pmatrix}

\begin{pmatrix} 2 \\ m \end{pmatrix}

\begin{pmatrix} 12 \\ 14.5 \end{pmatrix}

, find the value of m.

Solution:

Concept:

Matrix multiplication and equating corresponding elements of equal matrices.

Explanation:

Compute the left-hand side product.

\begin{pmatrix} 6 & 4 \\ 7 & 5 \end{pmatrix}\begin{pmatrix} 2 \\ m \end{pmatrix} = \begin{pmatrix} 6(2) + 4(m) \\ 7(2) + 5(m) \end{pmatrix} = \begin{pmatrix} 12 + 4m \\ 14 + 5m \end{pmatrix}

Simplify the right-hand side.

2\begin{pmatrix} 12 \\ 14.5 \end{pmatrix} = \begin{pmatrix} 24 \\ 29 \end{pmatrix}

Equate the first row:

12 + 4m = 24

4m = 12

m = 3

Check with the second row:

14 + 5m = 29

5m = 15

m = 3

Answer:

m = 3

, which is option C.

Go to Question:

Prev Question

Next Question