若|2x+4|+|6-2y|=0,求x的平方-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 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 y满足x^2+y^2-2x+4y=0求x-2y的最大值 x^2+y^2+6x-4y+13=0求x,y,x^2-y^2的值 若x^2+y^2-10x-6y+34=0,求（x-y)/(x+y)的值 已知：4x^2+y^2-4x-6y+10=0,求y/x-x/y的值 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 x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 若实数x,y满足x²+y²-2x+4y=0,求x-y的最大值 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*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 RT,若（√2x-y）+y^2+4y+4=0,求[(x-y)^2+(x+y)(x-y)]÷2x的值 计算(1) (x+y)(-x-y)(x+y)² (2) (-1/3x²y³)³(3) 若x²+3x-2=0,求2x³+6x²-4x+2的值 若X-2Y+6+（X+Y+12）²=0,求4X+ 5Y的值若X-2Y+6的绝对值+（X+Y+12）²=0，求4X+ 5Y 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！ 若x^2+y^2+6x-4y+13=0,求x^-y的值