Write as:
#(5sqrt(10))/(3sqrt(6))+(9sqrt(3))/(3sqrt(6))#
#=(5sqrt(10)+9sqrt(3))/(3sqrt(6))#
Getting rid of the root in the denominator
#color(green)(=(5sqrt(10)+9sqrt(3))/(3sqrt(6))color(red)(xx1)" "->" "(5sqrt(10)+9sqrt(3))/(3sqrt(6))color(red)(xx(sqrt(6))/(sqrt(6))))" #
#" "color(green)((5sqrt(10xx6)+9sqrt(3xx6))/(3(sqrt(6))^2))#
#" "color(green)((5sqrt(10xx6)+9sqrt(3xx6))/(18)#
#" "color(green)((5sqrt(2xx5xx2xx3)+9sqrt(3xx3xx2))/(18)#
#" "color(green)((10sqrt(15)+27sqrt(2))/(18)#
#" "color(green)((5sqrt(15))/9+(3sqrt(2))/2)#