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

so.. .we know the first term is -13, and the 43rd term's value is 449...so...this is an arithmetic sequence, thus, in order for us to get from -13 to 449 in 43 hops, we had to add "d" the common difference, 42 times.

so -13, -13 + d, (-13+d)+d, (-13+d+d)+d, ..... and so on.

but in short d + d + d + ... 42 times is just 42d

so, we know that