Customers of a phone company can choose between two service plans for long distance calls. The first plan has a $28 monthly fee and charges an additional $0.07 for each minute of calls. The second plan has a $14 monthly fee and charges an additional $0.12 for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

b) k’(6, 4); l’(3, 3)

step-by-step explanation:

a 270° clockwise rotation maps every point (x, y) to (y, -x). (it negates the x-coordinate and then switches it and the y-coordinate.)

this means the endpoints of the side congruent to kl, k' and l', would be mapped as:

k'(-4, 6)→(6, 4)

l'(-3, 3)→(3, 3)