Given that M = \(\begin{pmatrix} 3 & 2 \\ -1 & 4 \end{pmatrix}\) and N = \(\begin{pmatrix} 5 & 6 \\ -2 & -3 \end{pmatrix}\), calculate (3M - 2N)

  • A \(\begin{pmatrix} 1 & 6 \\ 1 & 18 \end{pmatrix}\)
  • B \(\begin{pmatrix} -1 & -6 \\ 1 & 18 \end{pmatrix}\)
  • C \(\begin{pmatrix} 1 & 6 \\ -1 & -18 \end{pmatrix}\)
  • D \(\begin{pmatrix} -1 & -6 \\ -1 & -18 \end{pmatrix}\)
waec 2021furthermathematics

The correct answer is B. \(\begin{pmatrix} -1 & -6 \\ 1 & 18 \end{pmatrix}\)

3M = 3 \(\begin{pmatrix} 3 & 2 \\ -1 & 4 \end{pmatrix}\)

 = \(\begin{pmatrix} 9 & 6 \\ -3 & 12 \end{pmatrix}\)

2N = 2 \(\begin{pmatrix} 5 & 6 \\ -2 & -3 \end{pmatrix}\) 

= \(\begin{pmatrix} 10 & 12 \\ -4 & -6 \end{pmatrix}\)

(3M - 2N) = \(\begin{pmatrix} 9 & 6 \\ -3 & 12 \end{pmatrix}\) - \(\begin{pmatrix} 10 & 12 \\ -4 & -6 \end{pmatrix}\)

Previous question Next question