Does anyone know what 3+10 is?

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.

Which expression gives the exact value of x?

Ebert used to make $22 an hour, but got a 10% raise. how much more will he make in a 40 hour work week with raise?