Finding area between curves: why did I get a negative answer

[phillyolly]

Homework Statement

Sketch the region enclosed by the given curves. Decide
whether to integrate with respect to x or y. Draw a typical approximating
rectangle and label its height and width. Then find the
area of the region.

Homework Equations

The Attempt at a Solution

My result gave me an answer "-20". The area cannot be negative, please check my answer for a mistake?

 

[Dick]

If you want to find the area between two curves f(x) and g(x), how do you know whether to integrate f(x)-g(x) or g(x)-f(x)? Use your graph.

 

[phillyolly]

OK, I got it. This is my try. Thank you.

 

[Dick]

Yes, that's right.