已知3x^2-4xy-7y^2+13x-37y+m=0可以分成2个一次因式的乘积求 m

已知x-y=8 xy=7,则3xy-2x+2y+4(y-x)²=? 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 已知x+y=4,xy=2,求代数式2(3x+2xy)+(2xy+3x+2y)-(4xy-7y)的值 已知xy/x+y=3,则代数式2x-7xy+2y/-x+xy-y的值是多少? 已知x-y=4xy,求2x+3xy-2y/x-2xy-y的值 已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值! 已知x-y=3xy,求5x+2xy-5y/x-4xy-y的值 .已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x的相反数为y-6,y的倒数为2x,求出代数式(5xy+4x+7y)+3(2x-xy)-(4xy-3y)的值 已知x y=1,xy=-3,求2xy-4x 4(y-2(xy-x)) 已知xy^2=-2求xy（2x^3y^7+5x^2y 已知x/y=3/4 ,则3xy-2y/2x+4xy=? 已知x^2+y^2=7,xy=-1,求代数式：5x^2-(3xy+4y^2)-(11xy-2y^2)-7x^2 已知x^2+y^2=7,xy=-1,求代数式:5x^2-3xy-4y^2-11xy+2y^2-7x^2 已知x^2+y^2=7,xy=-2,5x^2-3xy-y^2-11xy+(-4x^2)-(-2y^2)的值 已知x-y的绝对值等于4,xy=-3,xy^2+x^2y=? 已知X+Y=5XY=-3求多项式2(2X-3Y-4XY)-(3X-7Y+2XY) 已知x+y=4,xy=2,求x+y+3xy的值