A fitness center charges a membership fee plus a fixed amount per day for each day the center is used. If Claire paid 105 for 30 days of use, and Adrian paid 123 for 39 days of use, how many dollars is the membership fee?

Guest Oct 22, 2017

#1**+1 **

Let's call the membership fee " a " and the cost per use " b " .

Claire paid a total of 105 for the membership and for 30 uses.

105 = a + 30b

Adrian paid a total of 123 for the membership and for 39 uses.

123 = a + 39b

123 - 105 = (a + 39b) - (a + 30b)

18 = a + 39b - a - 30b

18 = 9b

2 = b

Plug this in to one of the equations to find a .

105 = a + 30(2)

105 - 30(2) = a

45 = a

hectictar
Oct 22, 2017

#1**+1 **

Best Answer

Let's call the membership fee " a " and the cost per use " b " .

Claire paid a total of 105 for the membership and for 30 uses.

105 = a + 30b

Adrian paid a total of 123 for the membership and for 39 uses.

123 = a + 39b

123 - 105 = (a + 39b) - (a + 30b)

18 = a + 39b - a - 30b

18 = 9b

2 = b

Plug this in to one of the equations to find a .

105 = a + 30(2)

105 - 30(2) = a

45 = a

hectictar
Oct 22, 2017

#2**0 **

Hectictar: If you got $1 for every question you answered on this forum, you would be a very wealthy young woman !!.

Guest Oct 22, 2017

#3**0 **

She would have about 1500 dollars. Hardly wealthy.

However, if we, the members of web2.0calc, had a farthing for every wrong answer you gave, our wealth would exceed all that of the Earth since time immemorial.

Reference: https://web2.0calc.com/questions/algebra_49367#r2

Update Statistical counters:

Increment BB error count by 1: BB=(6.0244834478561245 E21) + 1

It seems **we are getting richer by the second**.

Personally, I’d give it all back, if you would just go away. In fact, I would I’d give it all back and pay __continuously compounded__ interest on it. . . . **In perpetuity.**

.

GingerAle
Oct 23, 2017