
Alexandra M. answered 08/23/22
Essay Coach, English, Math & Chemistry Tutor At University of Georgia
Hello,
To solve this problem, we can write the information they give us in the form of two equations. "J" is our joining fee, and "m" is the number of months at the gym.
Joining, plus three months, can be written as "j" for joining fee, plus 3 times the monthly fee.
This all equals $160 as they tell us. So, we can write this "sentence" as:
j + 3m = 160
Likewise, the joining fee, "j" plus 5 times the monthly fee, 5 times "m," equals $200. This can be written as:
j + 5m = 200
Now we have our system of equations, as shown below.
j + 3m = 160
j + 5m = 200
We can now solve this using the elimination method. We can subtract the second line from the first one to cancel out the J and solve for M.
j-j = 0, cancels out
3m - 5m = -2m
160 - 200 = -40
Which will give us:
-2m = -40.
If we divide both sides by -2 to isolate the m, we will get:
m = 20.
Now we know that m = 20, so the monthly fee is $20.
To solve for the joining fee, j, we will plug m = 20 back into the first line of the system, j + 3m = 160
Substituting m for 20 will give us j + 3(20) = 160
j + 60 = 160
Then, subtract 60 from both sides.
j = 160 - 60
j = 100
So, our joining fee "j" is 100 dollars.