Hi all, I'm very new to calculus and have been coping well so far but one thing has me stumped.

(30+5s)ds = 70 where s = 0 to 2

I've got the answer off a calculation website but I can't get my workings to reach this conclusion.

Heres what I have so far

30+(5s^2/2)

30+(5/2 x s^2)

subsituting with '2'

30+(5/2 x 2^2) = 40

substituting with '0'

30+(5/2 x 0^2) = 30

but I currently believe it is 2 minus 0 to get the result i.e 40 - 30

I'd like to just add the 2 results and get 70 but why am I adding instead of minusing?

Thanks in advance for any help at all.

John