Question

The value of $(\sqrt{15}+\sqrt{10})(\sqrt{15}-\sqrt{10})$ is equal to

• A. 2
• B. 5
• C. 6
• D. 7

Answer 1

The correct option is B 5

The given expression is $(\sqrt{15}+\sqrt{10})(\sqrt{15}-\sqrt{10})$

Using the identity $(a+b)(a-b)=a^2-b^2$,
we can simplify the given expression as follows:

$(\sqrt{15}+\sqrt{10})(\sqrt{15}-\sqrt{10})=(\sqrt{15}{)}^2-(\sqrt{10}{)}^2$
= $15-10$
= $5$