Question

How do you simplify the expression `(sqrt13+sqrt11)(sqrt13-sqrt11)`?

Answer 1

`2`

Explanation:

The expression is a notable product of this kind:
`(a+b)(a-b)=a^2-b^2`

So
`(sqrt13+sqrt11)(sqrt13-sqrt11)=(sqrt13)^2-(sqrt11)^2=13-11=2`