A retail store estimates that weekly sales s and weekly advvertising costs x (both in $) are related by . The current weekly advertising costs are $2,000, and these costs are increasing at a rate of $400 per week. Find the current rate of change of sales (in $).

An object is accelerating at a constant rate. its velocity in feet per second as a function of time in seconds can be modeled by the linear function v(t) = 2.5t. what does the dependent variable represent for this function? a) acceleration b) distance c) slope d) velocity