Question

Find the sum of the first 12 terms of the arithmetic series 32+27+22+...

Answer 1

54

Explanation:

The first twelve terms would be, in decreasing order, 32, 27, 22, 17, 12, 7,2, -3, -8,-13,-18,-23.

1. -23+22 = -1

2. -13+12 = -1

3. -18+17 = -1

4. -8+7 = -1

5. -3+2 = -1

Using these five facts, we can simplify this to 32+27 -5(1) = 32+27-5 = 54

Answer 2

Answer:77

32+27+22+17+12+7+2-3-8-13-15-18=77