Question

If $\left[\begin{array}{cc}r+4& 6\\ 3& 3\end{array}\right]=\left[\begin{array}{cc}5& r+5\\ r+2& 4\end{array}\right]$ then $r=$

• A. $1$
• B. $2$
• C. $3$
• D. $-1$

Answer 1

The correct option is A $1$

We know that two matrices are equal if and only if their corresponding elements are equal and are of same order.
Thus comparing corresponding elements we get, for the first entry of the given matrices $r+4=5$ and $r$ is satisfying other equations which are involving $r$.

$\Rightarrow r=1$
Hence option 'A' is correct choice.