若x-y=3/4,则5X-5Y= ,-X+Y+1/4=

若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若x/y=4/3 则3x+2y/2x-5y= 若3x=5y,则x:y=________,(x-y):y=______ （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) （5x+3y)(3y-5x)-(4x-y)(4y+x)= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) 若x-2y=5,则式子12-x+2y=.以知3x-4y=2x+y则x∶y= 若|2x-y+5|+(x+2y-4)的平方=0,则（2x-y)的三次方-（x-3y)(y-2x)的平方 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 x+y／y=5／4,则x／y=----------------