What is the meaning of the constant 435?

Question

A school club is raising money for a trip, and he is to reach $10,000. Their fundraising progress is modeled by the function of x equals 435 + 1200 X, where X is measured in weeks. 

Answer 1

"function of x equals 435 + 1200 x"   means

        f(x)         =      435  + 1200x               [this is math model for current amount of cash]

 

When x=0 (that is, at the very start of the fundraising effort), f(0)=$435.  The school club already has some money that can be applied to making the trip.

 

If x is measured in whole weeks (that is, integers), then:

    at the end of the first week, the club has $1635

    at the end of the second week, the club has $2835

     ...

    at the end of the eighth week, the club has $10,035 and has earned enough to make the trip.

 

The math for solving for x:

  10000 = 435 + 1200x

    9565 - 1200x                [subtract 435 from both sides]

    7.97 = x                  [divide both sizes by 1200]

      x = 8             After 8 weeks, the club has enough money for the trip.

Answer 2

Hi Bitty,

The function can not be dependent on itself because you imply X = 450 +1200X. I think it should be 

Y = 450 + 1200X, then Y is the total amount of money the club is planning to raise, and X is the number of weeks the club wants to take to reach the target the $10,000 amount.

Now if 

Y = 450 + 1200X , you can see that when X = 0

Y = 450 

$450 is the amount of the money the club start out with before it started raising money. To find out the number of weeks to raise the desire $10,000, replace Y with that amount

Y= 450 + 1200X

10,000 = 450 + 1200X

10000 -450 = 450 +1200X -450    [subtract 450 from both sides]

9550 =1200X

9550/1200 = 1200X/1200

7.96 = X

X = 7.96 weeks

For practical purposes you either round it to 8 weeks or 7 weeks,  6days and 17hrs