Question

Use the formula for finding the sum 1+2+3+...+n to discover a formula for finding the sum 8+16+24+...+8n.
The formula for the sum 8+16+24...+8n is S = ?

Answer 1

Do you mean the method of Gauss?

Answer 2

\[\sum_{i=1}^{n}i\]

Answer 3

now do it where it is 2i
1+2+4+8+16.... +n

Answer 4

but you can't just use 2i

Answer 5

because your first term is not 2

Answer 6

yeah 8i if your first term is 8 then an increment of twice the i term

Answer 7

@Loser66 sorry,
I was just demonstrating a pattern, not the answer. but since you already laid it out, might as well go all the way

Answer 8

nah it's cool I didn't even realize you were on it