Please help I think it’s 4.0cm2 I’m i right?

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.

25 ! i need asap! ! ill mark brainliest!

Solve the inequaliy: (x^2+2)(x−2)^2(6−2x)> 0