Question 374920
{{{(3sqrt(7) - 2sqrt(6))(3sqrt(7) + 2sqrt(6))}}}
You can just use FOIL to multiply these. Or, if you notice, this expression fits the left side of pattern: {{{(a-b)(a+b) = a^2-b^2}}}, with "a" being {{{3sqrt(7)}}} and "b" being {{{2sqrt(6)}}}. I like using the patterns when possible. So, according to the pattern, your expression will work out to be:
{{{(3sqrt(7))^2 - (2sqrt(6))^2}}}
which simplifies as follows:
{{{3^2*sqrt(7)^2 - 2^2*sqrt(6)^2}}}
9*7 - 4*6
63 - 24
39<br>
Note: If you use FOIL you should get exactly the same answer.