Question

(sqrt2+5sqrt10)(sqrt2-5sqrt10) multiply

Answer 1

put in calculator?

Answer 2

\[(a+b)(a-b)=a^2-b^2\]
\[(\sqrt{2}+5\sqrt{10})(\sqrt{2}-5\sqrt{10})=(\sqrt{2})^2-(5\sqrt{10})^2\]
\[=2-250=248\]

Answer 3

Thanks I appreciate the clarification. Sometimes a fresh pair of eyes :)