若x-y=3,则-x+5+y=( )

若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ 若3x=5y,则x:y=________,(x-y):y=______ 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) (5)若x/2=y/3(y不为0）则x/y=____,x+y/y=___,y/x-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x-y=3,则-x+5+y=( ) 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若2x=3y,则(x*x+y*y)/x*x=? 若x:y=3则x:(x+y)= 若(3x-2y)/(x+y)=2/3,则3x/5y= 若x-y=5,(x+y)²=3则x²+y²=? 若x/y=4/3 则3x+2y/2x-5y= 若5X-8Y=0,则X+3Y/X-3Y= 若X/Y=7/5,则Y-X/X+3Y= 若|x+y-3|+(x-y-5)^2=0,则x)^2-y^2=