来自牟世堂的问题
(1)把x3+2x2y+y3+2xy2在实数范围内因式分解;(2)已知x=2009−53,求代数式x2−2x+1x2−11+x−3x+1+11−11+1x-2(cos30°)2的值.
(1)把x3+2x2y+y3+2xy2在实数范围内因式分解;
(2)已知x=2009−5
3,求代数式x2−2x+1x2−11+x−3x+1+11−11+1x-2(cos30°)2的值.


(1)把x3+2x2y+y3+2xy2在实数范围内因式分解;(2)已知x=2009−53,求代数式x2−2x+1x2−11+x−3x+1+11−11+1x-2(cos30°)2的值.
(1)把x3+2x2y+y3+2xy2在实数范围内因式分解;
(2)已知x=2009−5
3,求代数式x2−2x+1x2−11+x−3x+1+11−11+1x-2(cos30°)2的值.
(1)x3+2x2y+y3+2xy2=(x+y)(x2-xy+y2)+2xy(x+y)=(x+y)(x2+xy+y2);
(2)原式=(x−1)