=1-1/4+3\28+3\70+3\130+3\208
=1-1/7+3\70+3\130+3\208
=1-1/10+3\130+3\208
=1-1/13+3\208
=1-13/208
=1-1/16
=15/16
3/4=1-1/4
3/28=1/4-1/7
3/70=1/7-1/10
3/130=1/10-1/13
3/208=1/13-1/16
和=1-1/16=15/16
愿式=(1-1/4)+(1/4-1/7)+(1/7-1/10)+(1/10-1/13)+(1/13-1/16)
=15/16
=(1-1/4)+(1/4-1/7)+(1/7-1/10)+(1/10-1/13)+(1/13-1/16)=15/16
3\4+3\28+3\70+3\130+3\208
=1-1/4
+1/4-1/7
+1/7-1/10
+1/10-1/13
+1/13-1/16
=1-1/16
=15/16