Question

1+2+3+4+...........+n=? plz plz answer this question . and explain this​

Answer 1

a = 1

d = 1

n = n

sum of n terms = n(2+(n-1)1)/2

= n(n+1)/2

Answer 2

Answer:

here,

a=1,d=1

so,by using formula

S(n)=n/2{2a+(n-1)d}=n(n+1)/2✓✓✓

hope it helps... please mark it as brainlist.