Permutation and Combinations — MATHS STD 11 Science — Question

2. 3

Solution:

$\text{a}^{2}-\text{a}=2+4$

$\Rightarrow \text{a}^{2}-\text{a}-6=0$

$\Rightarrow \text{a}^{2}-3\text{a}+2\text{a}-6=0$

$\Rightarrow \text{a}(\text{a}-3)+2(\text{a}-3)=0$

$\Rightarrow (\text{a}+2)(\text{a}-3)=0$

$\Rightarrow \text{a}=-2,\text{a}=3$

$\text{a}=3$