Write a formula that will them decide how much each friend will have to pay.
let's let
w = price per mile
x = number of miles traveled
y = number of friends in the cab
z = cost for each friend

Okay so since we have all the variables, we can go ahead and make our formula. So our equation would look like z = (w/x) divided by y . This is because z would be the sum of the x miles divided by the cost of each mile (w). And then we would divide what we got in the parenthesis by y (friends). 

your choices area. when  , the function decreases from left to right b. the function has a y-intercept of  c. the graph of this function will be identical to the graph of  , if    and  .d. if c > 0 and r > 0, then the graph will only have positive y-values.    choice a is wrong.if you look at choice a: if  , then c is positive.when c is positive, then the only other thing that can make the exponential function be increasing or decreasing is  .they did not put any restrictions  for  , meaning this is a claim that applies for all possible values or r.  but if we say that  and , our function would look likewhich is an increasing function, from left to right. the growth factor of 1.5 increases the initial value of 10 as t goes up.  we showed a counterexample—an example when the claim does not work. so we can say this is false.choice a is false.if you look at choice b: the y-intercept is where the graph of the function intercepts the y-axis. since the y-axis is at t=0, plugging in yieldsbecause anything to the power of 0 is 1. since when  , the point  is on the graph of  .so choice  b is true.if you look at choice c: it is just a substitution. so it is also true.if you look at choice d: c > 0 means that there will be no reflections in the horizontal axis. we have no vertical translations either.all exponential functions that have no vertical translations or reflections in the horizontal axis will have only positive y-values. raising a real number to an exponent will never result in a negative numberso d is true.the only thing false is a. so a.