8x times 5 to the power of 3 would equal -1000x, right?

Can some one me with these questions

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.

Look at the chart showing the results of a baseball player at bat. which is the probability of getting a hit?