Question

已知y=根号(x-8)+根号(8-x)+18,求代数式[(x+y)/(根号x+根号y)]-2xy/(x根号y-y根号x)

Answer 1

y=根号(x-8)+根号(8-x)+18,

x-8≥0,8-x≥0

x=8,y=18

[(x+y)/(根号x+根号y)]-2xy/(x根号y-y根号x)

=26/(2√2+3√2)-288/(8*3√2-18*2√2)

=149√2/15