先化简，再求值：（x²）³÷x⁴﹣（x+2）（x﹣2）+（x+1）²，其中x=﹣ $\frac{1}{2}$ ．

    Do you want to be a basketball player like Kobe Bryant or Yao Ming? Come to join us! We have many sports clubs: basketball, table tennis, football, volleyball, and more. The price is 5 dollars for each lesson.

    Do you want to join our sports clubs? Please call Mr White. He plays basketball very well. His telephone number is 481-1324. Or you can call Miss Jones at 481-1327. She is our tennis coach. She is good with the students.

“塔吊”是建筑工地上普遍使用的一种起重设备，如图所示是“塔吊”的简化图．OB是竖直支架，ED是水平臂，OE段叫平衡臂，E端装有配重体，OD段叫吊臂，C处装有滑轮，可以在O、D之间移动．已知OE=10m，OC=15m，CD=10m，若在C点用此塔吊能起吊重物的最大质量是1.5×10³Kg，则：