Idon't know how to take the situation and make it into a slope and y intersection

Given the function f(x) = 3x + 1, evaluate f(a + 1). a. 3a + 1 b. a + 2 c. 3a + 4

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.

Jared had 3/7 of the minutes on a family phone plan remaining for the month. the plan is shared by 2 people. if divided equally what portion of the minutes remaining on the phone plan would be avalible for each person