Express-n-1-49-1-n-n-2-1-as-a-b-2-for-some-integers-a-and-b- Tinku Tara June 3, 2023 Number Theory FacebookTweetPin Question Number 131484 by bemath last updated on 05/Feb/21 Express∑49n=11n+n2−1asa+b2forsomeintegersaandb Answered by benjo_mathlover last updated on 05/Feb/21 Answered by mr W last updated on 05/Feb/21 1n+n2−1=n−n2−1=n−(n−1)(n+1)=n−12+n+12−2(n−12)(n+12)=(n−12)2+(n+12)2−2(n−12)(n+12)=(n+12−n−12)2=n+12−n−12∑49n=1(n+12−n−12)=∑50n=2k2−∑48k=0k2=(∑48k=0k2+492+502−12−02)−∑48k=0k2=492+502−12−02=72+5−12=5+62=5+32 Answered by Dwaipayan Shikari last updated on 05/Feb/21 n+n2−1=n+n2−n2+12+n−n2−n2+12=n+12−n−12∑49n=11n+12−n−12=12∑49n=1n+1−n−1=12(2−0+3−1+4−2+….+49−47+50−48)=12(52+49−1)=5+32 Terms of Service Privacy Policy Contact: info@tinkutara.com FacebookTweetPin Post navigation Previous Previous post: Question-65951Next Next post: f-x-y-x-x-4-y-2-y-x-2-y-4-g-x-y-x-f-x-y-f-y-g-1-1-