Question

(2 root 3 + root 5) (2 root 3 - root 5)​

Answer 1

Answer:

7

Step-by-step explanation:

Given,

$(2 \sqrt{3} + \sqrt{5} )(2 \sqrt{3} - \sqrt{5} )$

Since,

$(a + b)(a - b) = {a}^{2} - {b}^{2}$

Then,

$= {(2 \sqrt{3} )}^{2} - { (\sqrt{5} ) }^{2}$

$= (2 \times 2 \times \sqrt{3} \times \sqrt{3} ) - ( \sqrt{5} \times \sqrt{5} )$

$= (4 \times 3) - 5$

$= 12 - 5$

= 7 (Ans)