y=(x+1)^2/3(x-5)^2的极值,

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (x+2y)(x-2y)-(2x-y)的平方+(3x-y)(2x-5y)其中x=-1 y=13分之1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) { (x+y)/5+(x-y)/2=3 (x+y)/5-(x-y)/2=1的答案是多少, {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 分式的加减:[(x/y-y/x)除以（x+y）+x（1/y-1/x)]除以1+x/y,其中x=5,y=2 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y=-1/2 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(x+2009y)的值. 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(x+2009y)的值. 5x=3y,(2x+y)的平方=5x(x+y)+9 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 1、(-y^3)^5/y^3/ y^2+2(-y)^102、(x-y)^7/(y-x)^6+(x+y)^3/(x+y)^23、已知X^a=5,x^b=3,求X^(3a-2b)的值 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 [(x减2y)的2次方-(x+y)(3x-y)-5y的2次方]*(2x)其中x=-2y=1快地 化简求值【(x+2Y)的平方-（x+Y)（3x-Y)-5y的平方】÷（2x),其中x=-2,y=2/1 1:4(x-100)+3y=5 2:6(x-y)-2(x+y )=14 x-100=-y 3(x-y)+(x+y)=5 先无视上面的1.4(x-100)+3y=5x-100=-y2.6(x-y)-2(x+y )=143(x-y)+(x+y)=5 先因式分解,再求值:2x(x-y)-5y(y-x)+3(x-y)的平方,其中x=-1,y=2