Given the matrix \[ A = \begin{vmatrix} 3 & -2 \\ 1 & 6 \end{vmatrix} \] Find the inverse of matrix A.

Assessment: JAMB UTME - Mathematics - 2019 Subject: General Mathematics

Question 1 Report

| \begin{matrix} 6 & 2 \\ 1 & 6 \end{matrix} |

| \begin{matrix} \frac{2}{11} & \frac{1}{12} \\ \frac{3}{20} & \frac{1}{10} \end{matrix} |

| \begin{matrix} - 3 & 2 \\ - 1 & - 6 \end{matrix} |

| \begin{matrix} \frac{3}{10} & \frac{1}{10} \\ \frac{- 1}{20} & \frac{3}{20} \end{matrix} |

Answer Details

A = | \begin{matrix} 3 & - 2 \\ 1 & 6 \end{matrix} |

|A| = (3 x 6) - (-2 x 1)
= 18 + 2
= 20.
A

^{- 1}

\frac{1}{20} | \begin{matrix} 6 & 2 \\ - 1 & 3 \end{matrix} |

| \begin{matrix} \frac{6}{20} & \frac{2}{20} \\ \frac{- 1}{20} & \frac{3}{20} \end{matrix} |

| \begin{matrix} \frac{3}{10} & \frac{1}{10} \\ \frac{- 1}{20} & \frac{3}{20} \end{matrix} |

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