已知（x+3）²+|x-y+10|=0,求5x²y-[2x²y-(3xy-xy²

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/07/06 01:02:14

已知（x+3）²+|x-y+10|=0,求5x²y-[2x²y-(3xy-xy²）-3x]-2xy²-y²的值.

（x+3）²+|x-y+10|=0
（x+3）²=0 x=-3
|x-y+10|=0 y=7
5x²y-[2x²y-(3xy-xy²）-3x]-2xy²-y²
=5x²y-2x²y+3xy-xy²+3x-2xy²-y²
=3x²y-3xy²+3xy+3x-y²
=3*9*7+3*3*49-3*3*7-3*3-49
=189+441-72-49
=509

已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值已知x/y=3,求x²+2xy-3y²/x²-2xy+y² 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值已知（x+2）²+|x+y+5|=0,求3x²y+{-2x²y-[-2xy+（x² |x+2y+3|+(2x+y)²=0求x²-xy+y² 已知x²y²+x²+y²=10xy-16 求x,y 已知x²+y²=3xy且xy≠0,求x²y－²+x－²y²的已知3x²+xy-2y²=0(x≠0,y≠0),求x/y-y/x-x²+y²/x 已知x/y=3,求x²+2xy-3y²/x²-xy+y³的值 x/y=2,求分式x²-xy+3y²/x²+xy+6y² 问已知x²+y²=7,xy=－2,求5x²-3xy-4y²-11xy-7x&su 已知|x+2|+(y+1²=0,求x²+(2xy-3y²)-2(x²+xy-2y