How do you multiply $(5+2sqrt6)(2+sqrt6)$ ?

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Answer 1 · 2015-04-07T12:04:45

In general
$(a+b)*(c+d) = (a+b)c + (a+b)d$

So we can re-write
$(5+2sqrt(6))(2+sqrt(6))$
as
$(5+2sqrt(6))(2) + (5+sqrt(6))(sqrt(6))$

$= (10 + 4sqrt(6)) + (5sqrt(6) + 6)$

$= 16 + 9sqrt(6)$

How do you multiply (5+2sqrt6)(2+sqrt6)(5+2sqrt6)(2+sqrt6)?