The function y = 14 +2.31x + 4.50 can be used to determine the cost in dollars for an Uber ride of x miles which takes no longer than 10 minutes. What is the rate of change of the cost in dollars with respect to the number of miles?

Step-by-step explanation:

step one:

Given the function

y = 14 +2.31x + 4.50

we can solve for the rate of change by applying differentiation.

step two:

differentiating y which is cost with respect to x which is the miles

dy/dx= 0+2.32+0

dy/dx=2.32

Hence the rate of change of cost in the dollar to a mile is

2.32dollar/mile

there are lots of ways.   pick's theorem tells us if the vertices are lattice points the area a is

a = b/2 + i - 1

where b is the number of boundary lattice points and i is the number of interior lattice points.

in the figure i count b=16, i=50 so

a = 8 + 50 - 1 = 57

let's try the shoelace formula.   the area is half the sum of the cross products of the sides.  

a(-2,6)   -2(2)-6(-5) = 26

b(-5,2)   -5(-3) - 2(-2) = 19

c(-2,-3) -2(-3) - (-3)(4) = 18

d(4,-3)   4(3) - (-3)(5) = 27

e(5,3)   5(3) - 3(1) = 12

f(1,3)     1(6) - 3(-2) = 12

a(-2,6)

each of the cross products is twice the area of the triangle with the associated side and one vertex the origin. so the area of abo=26/2=13.

area = (1/2) (26 + 19 +   18 + 27 + 12 + 12) = 57

that checks!