simplify 3(sqrt(7))/(1- (sqrt27))

Answer 1

"rationalize" the denominator.
3√27 / (1-√27) * (1+√27)/(1+√27)
3√27 (1+√27) / (1 - 27)
9√3(1+3√3) / -26
-9/26 (9+√3)