①已知1<X<3,化简│X-1│+│X-3│的值.

问题描述:

①已知1<X<3,化简│X-1│+│X-3│的值.
②计算:│1/101-1/102│+│1/102-1/103│+│1/103-1/104│=+…+│1/109-1/110│

①已知1<X<3,化简│X-1│+│X-3│=X-1+3-x=2
②计算:
│1/101-1/102│+│1/102-1/103│+│1/103-1/104│=+…+│1/109-1/110│
=1/101-1/102+1/102-1/103+1/103-1/104+…+1/109-1/110
=1/101-1/110
=9/11110