Question

What is the sum of the first 25 odd integers starting at -13?

a) 25
b) 0
c) 625
d) -625

Answer 1

The sum of the first 25 odd integers starting at -13 is 275.

Step-by-step explanation:

To find the sum of the first 25 odd integers starting at -13, we can use the formula for the sum of an arithmetic series: Sn = (n/2)(a1 + an), where Sn is the sum, n is the number of terms, a1 is the first term, and an is the last term.

In this case, n = 25, a1 = -13, and an = -13 + (2 x (25-1)) = -13 + 2(24) = -13 + 48 = 35.

Substituting these values into the formula, we get Sn = (25/2)(-13 + 35) = (25/2)(22) = 275.

Therefore, the sum of the first 25 odd integers starting at -13 is 275.