Matrices and Determinants - Jamb Mathematics Past Questions and Answers

Question 21:

• JAMB 1997

Determine x + y if \(\begin{pmatrix} 2 & -3 \\ -1 & 4 \end{pmatrix}\) \(\begin{pmatrix} x \\ y \end{pmatrix}\) = \(\begin{pmatrix}-1 \\ 8 \end{pmatrix}\)

A. 3
B. 4
C. 7
D. 12

Question 22:

• JAMB 1997

Find the non-zero positive value of x which satisfies the equation \(\begin{vmatrix} x & 1 & 0 \\ 1 & x & x \\ 0 & 1 & x\end{vmatrix}\) = 0

A. 2
B. 4
C. √3
D. √2
E. 1

Question 23:

• JAMB 1998

The determinant of matrix \(\begin{pmatrix} x & 1 & 0 \\ 1-x & 2 & 3 \\ 1 & 1+x & 4\end{pmatrix}\) in terms of x is

A. -3x² - 17
B. -3x² + 9x - 1
C. 3x² + 17
D. 3x² - 9x + 5

Question 24:

• JAMB 1998

Let = \(\begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}\) p = \(\begin{pmatrix} 2 & 3 \\ 4 & 5 \end{pmatrix}\) Q = \(\begin{pmatrix} u & 4+u \\ -2v & v \end{pmatrix}\) be 2 x 2 matrices such that PQ = 1. Find (u, v)

A. (-\(\frac{5}{2}\) - 1)
B. (-\(\frac{5}{2}\) - \(\frac{3}{2}\))
C. (-\(\frac{5}{6}\) - 1)
D. (\(\frac{5}{2}\) - \(\frac{3}{2}\))

Question 25:

• JAMB 2006

Find p, q for which \(\begin{pmatrix} 2p & 8 \\ 3 & -5q \end{pmatrix}\)\(\begin{pmatrix} 1 \\ 2\end{pmatrix}\)\(\begin{pmatrix}24 \\ -17\end{pmatrix}\)

A. -4
B. 45
C. 4,2
D. 2