If $\begin{bmatrix} a+b & 2\\5 & ab\end{bmatrix}=\begin{bmatrix}6&2 \\5&8\end{bmatrix}$ Then one set of values of a and b is :

4, 2

The correct answer is Option (1) → 4, 2

$\begin{bmatrix} a+b & 2\\5 & ab\end{bmatrix}=\begin{bmatrix}6&2 \\5&8\end{bmatrix}$

$⇒a+b=6$   ...(1)

$⇒ab=8$   ...(2)

from (1) and (2),

$\frac{8}{b}+b=6$

$8+b^2=6b$

$b^2-6b+8=0$

$(b-4)(b-2)=0$

$b=4\,or\,2$

$a=2\,or\,4$