What is the sum of the first 5000 terms with common differnce of 5 if the first term is -5? And what is the n?
for any AP, the sum of the first n terms,
Sn = n/2 (2a + (n-1)d)
You have a,n,d so just plug them in.
Sn = n/2 (2a + (n-1)d)
You have a,n,d so just plug them in.