How do you turn 11.6 into a fraction?

What is the solution set of the quadratic inequality x^2-5< or equal to 0

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.

Select all of the following expressions that are equal to 2.5.