mile markers along the highway tell drivers how many miles they have traveled from one location to another. suppose daniel sees mile marker 141 when he gets onto the highway and mile marker 67 when he exits the highway. how far did daniel travel on the highway?
a. 69 miles
b. 71 miles
c. 74 miles
d. 208 miles

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

The volume of a cube is 8 in to the 3rd power. how long is each side?

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?