15x^2-47xy+28y ^2

15x^2-47xy+28y ^2 15x^2-47xy+28y^2 已知15x^2-47xy+28y^2=0,求x/y的值 若x^2+xy+y=14,y^2+xy+x=28,求x+y 如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. 3X^2+XY+Y=15 求XY. x^2-xy/xy-y^2约分 （x^2+xy/x-y)/（xy/x-y)计算 6x^2y^2+xy-15 多项式 2*x*x-xy-15*y*y 分解因式 (-x-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) .(x+y-2)(x+y-2xy)+(xy-1)^2 (x^2-xy)y÷y-x/xy怎么做? x^2+xy=12,xy+y^2=15,求(x+y)^2-(x+y)(x-y) 2x²y-3(2xy-xy)-xy (x^2+2xy+y^2-4xy)*(x^2-2xy+y^2+4xy)