The rule below shows how Mr. Perez's long-distance phone company computes his monthly bill. Which answer expresses that rule in the form of an equation?

Multiply the number of minutes Mr. Perez spent on long-distance calls by $0.45, the long-distance rate. Then add $33, the flat monthly charge.

A. F(t) = $(0.45 t + 33)
B. F(t) = $t (0.45 + 33)
C. F(t) = $0.45 + t 33
D. F(t) = $0.45 (t + 33)

Question

The rule below shows how Mr. Perez's long-distance phone company computes his monthly bill. Which answer expresses that rule in the form of an equation?

Multiply the number of minutes Mr. Perez spent on long-distance calls by $0.45, the long-distance rate. Then add $33, the flat monthly charge.

 		A.	F(t) = $(0.45  t + 33)
 		B.	F(t) = $t  (0.45 + 33)
 		C.	F(t) = $0.45 + t  33
 		D.	F(t) = $0.45  (t + 33)

anonymous · Answer

$$F(t)=$(0.45t+33) $$
so A.
The total charge is a function of the time, T so the .45 long distance rate is multiplied by the amount of time spent. The flat monthly rate of 33 is a constant and is therefore not affected by the time. Another way to think of it is that time(T)=(total-flat rate)/long distance time rate