(x-18)÷18/y=(x-27)÷27/2y

18(x+y)^8(x-y)^7÷[3(x+y)^3(x-y)^3]^2 已知2y-3x+3=0 求(2y-3x)^3x-2y+3（3x-2y)-18÷（2y-3x) [(x∨2+y∨2)-(x-y)∨2+2y(x-y)]÷4y+4,其中2x-y=18先化简,后求值 「（x²+y²）-（x-y）²+2y（x-y）」÷4y,其中2x-y=18 (x-18)÷18/y=(x-27)÷27/2y 先化简后求值：[(x∨2+y∨2)-(x-y）∨2+(x-y)]÷4y+4其中2x-y=18 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x [(2x-y)(2x+y)+y(y-6x)]÷2x=? x+y-z=0 x+2y-z=3 2x-3y+2z=5 y÷3-x+1÷6=3 2（x-y÷2))=3(x+y÷18) 已知(x-y)÷4=(2x+y)=5,且2x-3y=18,求3x-5y的值.是“（x-y)÷4=(2x+y)÷5” 先化简,再求值:y(x-y)-x(x+y)/x²-y²÷x²+y²/x+y,其中x=2,y=-1 x²-4y² x+2y---------- ÷ --------分数线x²+2xy+y² x²+xyx²-4y² x+2y----------÷--------分数线x²+2xy+y² x²+xy(x+2y)(x-2y)x(x+y)=----------------(x+y)(x+y)(x+2y)(x-y)x=------(x+y)这样对了吗? 1-[(x-y)/(x+2y)]÷[(x+y)(x-y)/(x+2y)²] 1-[(x-y)/(x+2y)]÷[(x+y)(x-y)/(x+2y)²]= [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013先化简。在求值 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 先化简再求值：(x-y/x)÷[x-(2xy-y^2/x)],其中x=2013 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 [(2x+y)的2次方-y(y+4x)-2x]÷2x=