Question 371465
{{{(sqrt(11)+3sqrt(3))(sqrt(11)-3sqrt(3))}}}
The slow way to multiply this is with FOIL. The fast way is to recognize that these two factors fit the pattern {{{(a+b)(a-b) = a^2 - b^2}}} with "a" being {{{sqrt(11)}}} and "b" being {{{3sqrt(3)}}}. Using this pattern then we know that the product will be {{{a^2-b^2}}}:
{{{(sqrt(11))^2 - (3sqrt(3))^2}}}
which simplifies as follows:
11 - 27
-16