Question 210631: Courtney’s grandmother gives her $350 to take gymnastics lessons. The fee for the first month is $50 and each additional month is $30. How many months of gymnastics can Courtney take using her grandmother’s gift? 11months
11 months
Additional Month is x
30(x)+50=350
30x=300
X=10
I know answer but how do I set up formular?
Found 2 solutions by jim_thompson5910, MathTherapy:
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! Let C=total cost of lessons
So at first, the cost is $50. So no matter how long she stays, she'll be paying $50. So at first, the cost is 
Now let's say that she now decides to do another month on top of the first month. She's already paid $50, but she now has to pay an extra $30. So for one additional month, the cost is now  . If she does it for another month after that, she has to pay another $30, giving the cost of 
Now let's say that she does 8 additional months. This means that she has to pay 8 $30 fees. So the cost would be  (there are 8 thirty's here)
To save time and sanity, instead of adding repeated values, we can just multiply. So instead of having eight 30's out there, we can rewrite that part as  .
So in general, if she stays for 'x' additional months, you're going to add on 'x' charges of $30 which will cost  . Add this to the original cost of $50 to get the total charge 
Since we want to hold the cost to $350 (that's her budget), we simply make  and plug it in to get 
Note: you can rearrange the last equation to get 
Answer by MathTherapy(10555)  (Show Source):
You can put this solution on YOUR website! Courtney’s grandmother gives her $350 to take gymnastics lessons. The fee for the first month is $50 and each additional month is $30. How many months of gymnastics can Courtney take using her grandmother’s gift? 11months
11 months
Additional Month is x
30(x)+50=350
30x=300
X=10
I know answer but how do I set up formular?
First of all, let's make the amount of months she can take lessons be M
The 1st month, therefore, would be counted as 1 month, at $50
The other months would then be M - 1, at $30
Therefore, we have the equation: 1(50) + (M - 1)30 = 350
Solving for M, we get: 50 + 30M - 30 = 350
30M + 20 = 350
30M = 330
Thus, the total amount of months that she can take lessons, or M is: 
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