Question

Multiply.
(4-√10)(2+5√6)
Simplify your answer as much as possible.

Answer 1

foil this actually

Answer 2

\[(4-\sqrt{10}) (2+5\sqrt{6}) =4*2 +4*5\sqrt{6}-\sqrt{10}*2-\sqrt{10}*5\sqrt{6}\]

Answer 3

\[=8+20\sqrt{6}-2\sqrt{10}-5*\sqrt{5}*\sqrt{2}*\sqrt{2}*\sqrt{3}\]

Answer 4

\[=8+20\sqrt{6}-2\sqrt{10}-10\sqrt{15}\]
here\[\sqrt{2}*\sqrt{2} =2\]

Answer 5

Can you point to any khan academy / anywhere else that can teach me more about solving these types of problems? Thank you.

Answer 6

Here is a simpler type problem from Khan Academy,
https://www.youtube.com/watch?v=yAH3722GrP8


It involves a "variable", x, which your problem did not,
but maybe it can still be of some help.

@fishstix