当x=-1/3时,【十万火急!】化简求值：(9x^2y-6xy^2)÷(-3xy)-【(4y^2-9x^2)/(-3x+

当x=-1/3时,【十万火急!】化简求值：(9x^2y-6xy^2)÷(-3xy)-【(4y^2-9x^2)/(-3x+ 化简求值:根号x^-2xy+y^2 + x^2 -6xy+9y^2/x-3y,其中x=根号3,y=根号5 化简求值,若X方-2XY+Y方+1XY-11=0,求X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y的值 化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1, 化简求值3x²y-[2xy-2（xy-3/2x²y)+xy]+3xy²其中x=3、y=-1 ①化简求值:2(x^2y+xy)-3(x^2y-xy)-4x^2y,其中x=1,y=-1. 化简求值：2（x的平方y+xy）-3（x平方y+xy）-4x平方y,其中x=-1,y=2 化简求值[1-(2x/x+y）]÷ （x²-2xy+y²/3x+3y）+（x²+xy/x& 化简求值3x²y-[2xy²-2(xy-3/2x²y)+xy]+3xy² ,当x 先化简再求值：xy^3÷(-xy)+(x+2y)(x-2y),其中x=根号2,y=1 (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) 先化简,再求值：（6x-2y)*3/2xy^2-(xy-3)(xy+1)-(3x-4y)(3x+4y)+(2x-1/2y