Question

Find the sum of -5,-8,-11-----------(-230)​

Answer 1

answer

-14 -17 -20 -23 -26-29-32-35-38-41-44-47-50-53-56-59-62-65

Answer 2

This question from AP (airthmetic progression) chapter

here,

a=-5, d= {-8-(-5)}=-3

an=-230

a+(n-1)d= -230

-5+(n-1)-3= -230

(n-1)-3= -230+5

(n-1)=-225÷ -3

(n-1)=75

n=75+1

n=76

now,

sn(sum)=n/2(a+an)

sn=76/2{-5+(-230)}

sn=38{-5-230}

sn=38{-235}

sn=-8930

hence, sum of these numbers is -8930