式子化简x2-2x≥-2y+y2,变(x−y)(x+y−2)≥0 怎么化(x−y)(x+y−2)≥0化简x^2-2x≥-2y+y^2

式子化简x2-2x≥-2y+y2,变(x−y)(x+y−2)≥0 怎么化(x−y)(x+y−2)≥0化简x^2-2x≥-2y+y^2 已知x、y为实数,求式子x2+y2+2x-4y+7的最小值 ∫∫(x2+y2-(x+y)/√2)dσ=∫∫(x2+y2)dσ,满足x2+y2≤1,式子为什么成立? x2-2x+2y-y2因式分解 (x2-4y2)-(x+2y)因式分解 因式分解(x2-y2)-(x-y)2快 设x,y,z∈R+,求证 2z2-x2-y2/(x+y)+2x2-y2-z2/(y+z)≥x2+z2-2y2/(x+z) 设x,y,z∈R+,求证 2z2-x2-y2/(x+y)+2x2-y2-z2/(y+z)≥x2+z2-2y2/(x+z) 化简求值：(x2+y2)(x2-y2)-(x+y)2(x-y)2,其中x= 4,y=1/4. 化简求值x2+3xy2y2分之-2x2-xy+y2,其中x=2y 计算(x+y/x-y + 4xy/y2-x2)(x2-9y2)/（x2+2xy-3y2） x2+y2+x+y=18 x2+y2-2x-4x=24 解方程组 因式分解；x2[x-y]+y2[x-y]2是平方 因式分解：25x2-(2x-y)2 x2+2xy+y2-1 (a2+1)2-4a2 a6-a2 25x2-(2x-y)2 x2+2xy+y2-1 (a2+1)2-4a2 a6-a2四个式子 4x2-y2/x2-2xy+y2 +(2x-y)/2x2-2xy y=x+√(1-x2) y2=x2+(1-x2)+2x√(1-x2) x2-2xy+y2=4 x2+y2-x-y=6 解不等式x2-2xy+y2=4 x2+y2-x-y=6 解不等式 已知x,y满足（x2+y2）(x2+y2-1)=2,则x2+y2的值为多少?x2,y2表示x和y的平方