====== Question 7, Exercise 2.2 ======
Solutions of Question 7 of Exercise 2.2 of Unit 02: Matrices and Determinants. This is unit of A Textbook of Mathematics for Grade XI is published by Khyber Pakhtunkhwa Textbook Board (KPTB or KPTBB) Peshawar, Pakistan.
=====Question 7(i)=====
Evaluate $\left| \begin{matrix}3860 & 3861  \\3862 & 3863 \end{matrix} \right|$
====Solution====
Given
$$\left| \begin{matrix}
   3860 & 3861  \\
   3862 & 3863  \\
\end{matrix} \right|=14911180-14911182$$
$$=-2$$ 



=====Question 7(ii)=====
Evaluate $\left| \begin{matrix}81 & 82 & 83  \\84 & 85 & 86  \\87 & 88 & 89\end{matrix} \right|$
====Solution====
Given
$$\left| \begin{matrix}
   81 & 82 & 83  \\
   84 & 85 & 86  \\
   87 & 88 & 89  \\
\end{matrix} \right|=81(7565-7568)-82(7476-7482)+83(7392-7395)$$
$$=-243+492-249$$
$$=0$$ 



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