Question 761533
The expression is:

{{{(sqrt(3) - sqrt(-36)) * (sqrt(3) + sqrt(-36))}}}

We can use the identity {{{(a - b) * (a + b) = (a^2 - b^2)}}} which works for complex numbers too.

Hence

{{{(sqrt(3) - sqrt(-36)) * (sqrt(3) + sqrt(-36))}}}

=

{{{3 - (-36)}}}  =  {{{3 + 36 = 39}}}


:)