# Math Help - calculating definate intregals

1. ## calculating definate intregals

Let .
Find
and Let .

Find
and

So I found the first one, which is just 0.

How do I find the seecond one? I don't get the logic of it...

2. $
\int_{-1}^{-3.5}(10f(x)-3)dx=-\int_{-3.5}^{-1}(10f(x)-3)dx=-10\int_{-3.5}^{-1}f(x)dx+3\int_{-3.5}^{-1}dx
$

3. wouldn't it just be -10 (0) + 3(0) which is just zero? but that answer is wrong...

4. $
\int_{-3.5}^{-1}dx=x|_{-3.5}^{-1}=(-1)-(-3.5)=2.5
$

5. Sorry I still don't get it. What is dx or x in this problem? If I wsa given that, I could figure it ou, I know how to be integration...