4√6+√24-√54=
√9m-6√m+2√25m=
(√200-√2)×√2=
(√x+√y)×(√y-√x)+x=
(√a+√b)²-a-b=

4√6+√(4*6)-√(9*6)=4√6+2√6-3√6=3√63√m-6√m+2*5√m=7√m√(200*2)-√(2*2)=20-2=18√xy-x^2+y^2-√xy+x=-x^2+x+y^2(√a)^2+√ab+√ab+(√b)^2-a-b=a+2√ab+b-a-b = 2√ab