(|x+1|+|x-2|) >= (|(x+1)-(x-2)|)=3
(|y+1|+|y-2|) >= (|(y+1)-(y-2)|)=3
(|z-3|+|z+1|) >= (|(z-3)-(z+1)|)=4
在滿足上述條件的情況下,36只能分解為3x3x4
則必有
(|x+1|+|x-2|)=3,當(dāng)-1<=x<=2時(shí),此條件滿足
(|y+1|+|y-2|)=3,當(dāng)-1<=y<=2時(shí),此條件滿足
(|z-3|+|z+1|)=4,當(dāng)-1<=z<=3時(shí),此條件滿足
則
最小值：x=y=z=-1,x+2y+3z = -6
最大值：x=y=2,z=3,x+2y+3z = 15