Question

Martin is interested in joining a gym and has researched the cost of two gyms close to his

house Gym A has a $50 registration fee and costs $30 per month. Gym B has a $100
registration fee and costs $10 per month. The cost of joining each gym can be modeled by the
expressions below, where m represents the number of months.
• Gym A: 30m + 50
• Gym B: 10m + 100

Answer 1

I suppose that you want to find which gym will be cheaper for you.

We have two equations:

• Gym A: 30m + 50

• Gym B: 10m + 100

First, let's find the value of m such that both gyms cost exactly the same:

30*m + 50 = 10*m + 100

Let's solve this for m

30*m - 10*m = 100 - 50

20*m = 50

m = 50/20 = 2.5

now:

for m < 2.5, Gym A will be cheaper, because the y-intercept is smaller.

for m > 2.5, Gym B will be cheaper, because the slope is smaller,

Then depending on the number of months that Martin wants to go to the gym, he can se the info above to pick the one that is cheaper.