Question

十万火急：请教高人这道题如何做？

Answer 1

=4/3+16/15+36/35+64/63+100/99+144/143

=（1+1/3）+（1+1/15）+（1+1/35）+（1+/63）+（1+/99）+（1+/143）

=6+（1/3+1/15+1/35+1/63+1/99+1/143）

=6+（2/3+2/15+2/35+2/63+2/99+2/143）/2

=6+（1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11+1/11-1/13）/2

=6+（1-1/13）/2

=6+6/13

=6又6/13

Answer 2

 

=(1*3+1)/(1*3)+(3*5+1)/(3*5)……

=7+1/(1*3)+1/(3*5)+……

=7+0.5*（1-1/3+1/3-1/5+1/5……+1/11-1/13)

=7+0.5*12/13

=97/13

 

 

Answer 3

原式=4/3+16/15+36/35+64/63+100/99+144/143
=1+1/3+1+1/15+1+1/35+1+1/63+1+1/99+1+1/143
=6+1/2*（1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11+1/11-1/13）
=6+1/2*（1-1/13）
=84/13