xy=(x-15)(y+6)

xy=(x-15)(y+6) |x|/x+y/|y|+xy/|xy|= 1-2/x+y=xy,4y+6x=xy.求xy的解? 当5xy/2x-y=2时,代数式2x-y/10xy的值是多少?代数式15xy/6x-3y的值是多少? 6x²-xy-15y²=0 求x²-2xy+4y²/2x²-3xy-3y²告诉下 6x²-xy-15y²=0 求2x²-3xy-3y²分之x²-2xy+4y² 3X^2+XY+Y=15 求XY. ( )*3xy=6x^2y+2xy^2 如果xy+x+y=6,试求自然数 xy 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) x+y=6,xy=8,求5x+xy+5y/x-xy+y的值 已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值. 已知(xy)/(x+y)=6求(3x-2xy+3y)/(-x+3xy-y)的值. 4xy-5x+6y=15如何因式分解 已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y答案是1/x-1/y=2(y-x)/xy=2 得：x-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy)=xy/(-7xy)=-1/7 谁能帮我解释一下=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy) 是怎 6x^2y^2+xy-15 |x|=5 |y|=6 xy 已知X+y=6,xy=7 求x^2y+xy^2=已知X+y=6,xy=7 x^2y+xy^2