??????????

admin

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

�� ????
?????????????�????�??????????????????????????????????????????
???????????????????????????????�????�?????????????????????????????????
??????????????????????????�????�????????????????????????
� �??????
?????????????�????�???????????????????????????
???????????�????�??????
� ????
?????
�� ????
???????????
1????????????????????????????????????????????????????????????????????????????????????????
�????????????????????????????�??PPT?????
??????????????
??????????????????????35?????????94????????????
2?????????????????????????????????
3??????�????�???????????????????????????????????????????????????????????????????????????????????????????
?????
????????????????????
?????????????
??????????????????????????????????�?????????????????6?????????20???????????�
1????????????????????????????????????????
????????????7????????20??? ?????2???????4?????????
2???????????????????????
??????????????????????????????7???
??????????????????????????
3???????????????????????????????????20??
???????
1??????
7�2=14??? �?????????????7 �2=14???
20-14=6??? �???????????4???????????????????????????6????????????
4-2=2??? ��????????????4????????????????4-2????????????????2????
6�2=3??? �? ��???????????????6??????????6?????2?????????????????6�2=3????????
7-3=4??? �? ??????????????????????7-3=4?�
??????????????????????????????????
????4�2+3�4=20??????4+3=7????
?????????????????????????????
?????????????????????????1500????????????ppt?????????????
?????????????????????
2??????
???????????????????????????
???????2????????4???????????????????????????????8???????????????????8???
????????????????????????????????????????????????????????????????????????
??????????????????ppt???
7�4=28??? ����28-20=8???���� ��4-2=2??? �
?? 8�2=4??? �����??7-4=3???
??????????????????????????1500????????????ppt?????????????
?????????????????????
??????????????????????????????????????????????????????????????????????????????
???????
??????????????????????????????????????
??????????????????????????????
????????????????????????
?????+????=????????+???=???????????
????????????????????????????????????????x???x?????????????????????????x?????????7?????????????? ?7-x??????????2?????x?????2x???????4????7-x?????4?7-x?????????????20?????2x+4?7-x?=20
1? ?????x?????7-x???
2x+4?7-x?=20
2? ?????x?????7-x???
4x+2?7-x?=20
???????????????????????????????????x???????????????????????????x?
??????????????????????????????????
????????????????????????????????????????
??????????????????1500????????????????????????????????????
??????????????????????????????????
???????????
1?????�???� ???�????�????
?1????????
?38?????????????8????????????????6???????4???????????
?????
?2???????�????�????????
?????????????????????????????????�????�???????????????�????�??????????????�????�???????????????????????ppt???????
????
?????????????????????????????
??????
????
?????
� � � � � � � � � � � ��????
� � � � � � � � � � � � � � � �???� � � � � � � � � � � � � � � � � � � � � ��???
� � � � ??????� � � � � � � � � � � � � � � � � � � �?????x?????7-x???
� � � � � � � � � � 7�2=2814??? 20-14=6???� � � � � � 2x+4?7-x?=20
� � � � � � � � � � � 4-2=2???� � � � � � � � � � � � � � � � � � � � � � � �2x+28-4x=20
� � �?? 6�2=3??? ??7-3=4???� � � � � � � � � � � � � � � �2x=8
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �x=4
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �7-4=3???
� � � �???????� � � � � � � � � � � � � � � � � ��?????x?????7-x???
� � � � � � � � � 7�4=28??? ��28-20=8???� � � � � � � � � 4x+2?7-x?=20
� � � � � � � � � � � 4-2=2???� � � � � � � � � � � � � � � � � � � � � � � � �4x+14-2x=20
� � � �?? 8�2=4??? ??7-4=3???� � � � � � � � � � � � � � 2x=6
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � x=3
� � � � � � � � � � � � � ��????4????3??� � � � � � � � � � � � � � � � � � �7-3=4???
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �????4????3??
� �?????

?�������??
????????????.docx�