An author is paid $500 as an advance on their book plus an additional $4 for every book sold. if the author earns $880, how many books has he or she sold?

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

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. y= 5x, y=7x^2then find the area s of the region.