Que. Find the sum to n terms: 1/1.3.5 +1/3.5.7 +1/5.7.9 +....... Share with your friends Share 3 Anuradha Sharma answered this Given series is, S= 11.3.5+13.5.7+15.7.9+17.9.11+.......+12n-12n+12n+3Now each term can be break down as, 11.3.5=1211.3-13.513.5.7=1213.5-15.7.....12n-12n+12n+3=1212n-1.2n+1-12n+1.2n+3Now putting the value we get, =1211.3-13.5+13.5-15.7+15.7-17.9+17.9-19.11.......+12n-1.2n+1-12n+1.2n+3Now we can see that term will get cancelled and first and last term will be left, =1213-12n+1.2n+3 -4 View Full Answer
