Given:
For gym A, initiation fee = $12 and cost = $10 per month.
For gym B, initiation fee = $20 and cost = $6 per month.
To find:
The equation that aims to find when these two gyms will cost the same amount of money,
Solution:
Let the number of months be x.
Cost function = Initiation fee + (cost)(x)
Cost function for gym A is
[tex]f(x)=12+10x[/tex]
Cost function for gym B is
[tex]g(x)=20+6x[/tex]
Cost of these two gyms are equal if f(x)=g(x).
[tex]12+10x=20+6x[/tex]
Therefore, the required equation is [tex]12+10x=20+6x[/tex].
On solving this equation, we get
[tex]10x-6x=20-12[/tex]
[tex]4x=8[/tex]
[tex]x=2[/tex]
Hence, after 2 months the cost of these two gyms are same.