sqrt(27x^2y)-sqrt(45xy^2)+sqrt(108x^2y)-sqrt(125xy^2)√27x2y−√45xy2+√108x2y−√125xy2
= sqrt(9x^2*3y)-sqrt(9y^2*5x)+sqrt(36x^2*3y)-sqrt(25y^2*5x)=√9x2⋅3y−√9y2⋅5x+√36x2⋅3y−√25y2⋅5x
= sqrt((3x)^2*3y)-sqrt((3y)^2*5x)+sqrt((6x)^2*3y)-sqrt((5y)^2*5x)=√(3x)2⋅3y−√(3y)2⋅5x+√(6x)2⋅3y−√(5y)2⋅5x
= sqrt((3x)^2)sqrt(3y)-sqrt((3y)^2)sqrt(5x)+sqrt((6x)^2)sqrt(3y)-sqrt((5y)^2)sqrt(5x)=√(3x)2√3y−√(3y)2√5x+√(6x)2√3y−√(5y)2√5x
= 3xsqrt(3y)-3ysqrt(5x)+6xsqrt(3y)-5ysqrt(5x)=3x√3y−3y√5x+6x√3y−5y√5x
= (3x+6x)sqrt(3y)-(3y+5y)sqrt(5x)=(3x+6x)√3y−(3y+5y)√5x
= 9xsqrt(3y)-8xsqrt(5x)=9x√3y−8x√5x