Is this right if not please tell me why??

[shaylee112]

With this session long project I was suppose to describe a function in my own life.



Each day at work I drink soda which I purchase from the snack bar. However I try to limit myself throughout the day to a set amount. Therefore the amount of money I spend depends on the number of sodas I buy. Thus my function would be number of dollars spent(D) = 4 times the soda (S) or D=4S.

is this the right way for the equasion or should it be flipped like the number of sodas drank = dollars spend HELP??!!??

 

[Unco]

If a "soda" is $4, then the amount spent in a day is
cost per soda ($4) * number of sodas (S),
ie. D = 4S.

You have done just this and are fine. You could flip it around:

number of sodas = total spent / cost per soda:
S = D/4.

Notice they are equivalent. If you know how many sodas you bought, you find the amount spent from the first one; if you know how much you spent, you use the second one to find the number of sodas bought.