先化简，再求值(11-2/x)/x²-4x+4/x-4-x+4/x+2，其中x²+2x-15=0

Question

如题所述

Answer 1

求值

Answer 2

因为x²+2x-15=0
解得x=-5, or x=3
(1-2/x)÷(x²-4x+4)/(x-4)-(x+4)/(x+2)
=(x-2)/x ×(x-4)/(x-2)^2-(x+4)/(x+2)
=(x-4)/[x(x-2)]-(x+4)/(x+2)
当x=-5时,
(x-4)/[x(x-2)]-(x+4)/(x+2)
=-9/35-(-5+4)/(-5+2)
=-9/35-1/3
=-27/105-35/105
=-62/105
当x=3时,
(x-4)/[x(x-2)]-(x+4)/(x+2)
=(3-4)/(3×1)-(3+4)/(3+2)
=-1/3-7/5
=-5/15-21/15
=-26/15
=-1又11/15本回答被提问者采纳

Answer 3