x^2+y^2-6x-4y-9=0,求2x-3y最大值最小值之和

已知x^2+y^2+13-4x+6y=0,求(2x-y)^2-2(2x-y)(x+2y)+(x+2y)^2 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的值 已知x^2-6xy+9y^2=0,求(x-y)/(x+y) 求x ,y 9x^2+4y^2-12x-8y+8=0 已知：x^2+y^2+4x-6y+13=0,求x^y值. x^2+y^2+4x-6y+13=0,求x^y的值 x^2-4x+y^2-6y+13=0求x,y的值 若x^2+y^2-6x+4y+13=0 求x+y 因式分解 若 x^2+4x+y^2-6y+13=0 求y^x 已知(x+y)(x+y-6)+9=0求2(x+y)的值 已知:(x+y)(x+y+6)+9=0 求2(x+y)的值 x^2+y^2+6x-4y+13=0求x,y,x^2-y^2的值 已知：4x^2+y^2-4x-6y+10=0,求y/x-x/y的值 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值