已知x分之1+y分之1=8,求x+2xy+y分之2x-3xy+2y的值

问题描述:

已知x分之1+y分之1=8,求x+2xy+y分之2x-3xy+2y的值

(2x-3xy+2y)/(x+2xy+y)
=(2/y-3+2/x)/(1/y+2+1/x) 分子分母同时除以xy
=[2(1/x+1/y)-3]/[(1/x+1/y)+2]
=(16-3)/(8+2)
=13/10