Question and Answers Forum

All Questions      Topic List

Arithmetic Questions

Previous in All Question      Next in All Question      

Previous in Arithmetic      Next in Arithmetic      

Question Number 199863 by Karanji last updated on 10/Nov/23

−5+(−8)+(−11)+...+(−230)

$$−\mathrm{5}+\left(−\mathrm{8}\right)+\left(−\mathrm{11}\right)+...+\left(−\mathrm{230}\right) \\ $$

Answered by som(math1967) last updated on 10/Nov/23

 c.d=(−8)−(−5)=−3  −230=−5 +(n−1)×−3  ⇒(n−1)=75  ⇒n=76  S_(76) =((76)/2){−10+75×(−3)}  =38×(−235)=−8930

$$\:{c}.{d}=\left(−\mathrm{8}\right)−\left(−\mathrm{5}\right)=−\mathrm{3} \\ $$$$−\mathrm{230}=−\mathrm{5}\:+\left({n}−\mathrm{1}\right)×−\mathrm{3} \\ $$$$\Rightarrow\left({n}−\mathrm{1}\right)=\mathrm{75} \\ $$$$\Rightarrow{n}=\mathrm{76} \\ $$$${S}_{\mathrm{76}} =\frac{\mathrm{76}}{\mathrm{2}}\left\{−\mathrm{10}+\mathrm{75}×\left(−\mathrm{3}\right)\right\} \\ $$$$=\mathrm{38}×\left(−\mathrm{235}\right)=−\mathrm{8930} \\ $$

Commented by Karanji last updated on 10/Nov/23

sirthankyou

$${sirthankyou} \\ $$

Commented by Karanji last updated on 10/Nov/23

happy diwali sir

$${happy}\:{diwali}\:{sir} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com