Question

What is the common difference of a 43-term arithmetic sequence where the first term is -13 and the sum is 9,374?

11
11.5
12
12.5

Answer 1

use

\[9374 =\frac{43}{2}[2\times( -13) + (43-1)4d]\]

simplify the equation

\[ 9374 = -559 +903 d\]

now solve for d

Answer 2

11?

Answer 3

thats what I calculated

Answer 4

thanks!