1.已知x,y满足2x+y=6,x-3y=1,求7y（x-3y）²-2（3y-x）³的值2.已知x+y=2,xy=-½,求x（x+y）²（1-y）-x（y+x）²的值

已知x,y满足约束条件 2x+5y>=10 2x-3y>=-6 2x+y 已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y 已知实数x,y满足2x+5y>=10;2x-3y>-6;2x+y 化简求值：已知x、y满足：x^2+y^2-4x+6y+13=0 求代数式 的值.(3x+y)^2-3(3x-y)(x+y)-(x-3y)(x+3y)急用！ 已知X和Y满足3X+4Y=2,X-Y-1/7 已知x和y满足3x+4y=2,x-y 已知x,y满足y 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知x=3y+2,且满足4y 已知x=3y+2,且满足4y 1.已知x,y满足2x+y=6,x-3y=1,求7y（x-3y）²-2（3y-x）³的值2.已知x+y=2,xy=-½,求x（x+y）²（1-y）-x（y+x）²的值 已知x,y∈R,满足x²+y²-4x-6y+12=0 1.y/x的范围,2.x²+y²的范围 3已知x,y∈R,满足x²+y²-4x-6y+12=01.y/x的范围,2.x²+y²的范围 3.x+y的范围 已知x,y满足x^2+y^2-6x+8y+25=0,求y^x的值 已知x、y满足：x^2+y^2+6x-10y+34=0,求y-x的值 已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x. 已知X,Y满足|X-Y-1|+（X+Y-3)^2=0求X,Y的值 已知x、y满足x2+y2-4x+6y+13=0 求代数式（3x+y)2-3(3x-y)(x+y)-(x-3y)(x+3y)已知x、y满足x^2+y^2-4x+6y+13=0 求代数式（3x+y)^2-3(3x-y)(x+y)-(x-3y)(x+3y)的值 已知实数x y满足x^3-6x^2-4=0,y^3-3y^2-9y-9=0求x-y