x⊕y=6x+5y,x△y=3xy 已知(2⊕3)△a=324 求a

已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y x²（x+y)(y-x)-xy(x+y)(x-y) 已知a+b=4,ab=-2,求多项式3a²b+3 已知关于xy的方程组 x-y=a+3,2x+y=5a 已知x,y>0 2x+y+3=xy 求5x+4y最小值 已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy 已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy 已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y) 已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y 已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值. 已知X+Y分之XY=2,求-X+3XY-Y分之3X+5XY+3Y