已知x+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.数学上交不不算请教下.

问题描述:

已知x+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.
数学上交不不算请教下.

x+4y-2x+8y+5=0, (x-1)+(2y+2)=0 ∵(x-1)≥0,(2y+2)≥0 ∴(x-1)=0,(2y+2)=0 x=1,y= -1 代入x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)即可求出
麻烦采纳,谢谢!