?????????????????????????????!

?????????

???????

“???????”“????”

??????????“???”

????????????

???????????

??????

?=???????????(?????)????+??????????+????

????????????????????????

?,????,??????????????,??????????????

???????:??????????????????“????????????”?

?????

??????????

?????,??????,??????????(???????????????/????),???,??????????

??????????

?,???

??????????????????????????????????

????????,??

??????????????????????????

??????????????,??

??????????

?????????,????4500????,??????????????????????4200?????,???????3600?????,?????????300????????

????????????????300?????????

????,??????????,???4200??-3600??????=600???

??

??

??????

“?????????????”????

?????????

?

“????????????????”???????

??????

?????????

?:“???????”????????????????????????????????

????:????? ??“???????????”

?? ????????????????????????

????:1????????????:??????????????

2?????vx

3???????

4???????

5?????

?????????????????????????????!

?????????

???????

“???????”“????”

??????????“???”

????????????

???????????

??????

?=???????????(?????)????+??????????+????

????????????????????????

?,????,??????????????,??????????????

???????:??????????????????“????????????”?

?????

??????????

?????,??????,??????????(???????????????/????),???,??????????

??????????

?,???

??????????????????????????????????

????????,??

??????????????????????????

??????????????,??

??????????

?????????,????4500????,??????????????????????4200?????,???????3600?????,?????????300????????

????????????????300?????????

????,??????????,???4200??-3600??????=600???

??

??

??????

“?????????????”????

?????????

?

“????????????????”???????

??????

?????????

?:“???????”????????????????????????????????

????:?????