x+y=6,xy=8,5x^2+5y^2=?

已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值 x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值 若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( ) √x(√x+2√y)=√y(6√x+5√y,求x-3√xy+2y/x+√xy-6y ∫x(∫x+2∫y)=∫y(6∫x+5∫y),求：（x+∫xy-y)/(2x+∫xy+3y) 已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值 [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- 已知x>0,y>0,且x+6y=5根号xy,求(2x+根号xy-y)分之(x+根号xy+2y)的值 f(x+y,x-y)=2x②+5xy+2y②+6求f(x,y) 若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2 xy=6,x-y=5,x^2y+xy^2 若x+y=5,xy=6,求x^2y+xy^2的值