Based on the question, a health club membership costs $80, plus $48 per month. This can be written as $80 + $48 per month = health membership cost.
If x = month and y = cost, then we can rewrite the equation as:
![\begin{gathered} 80+48x=y \\ or \\ y=48x+80 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/qyr8g9ok2tlacchcuheu79arck1pi5dmz9.png)
a. This is our equation in the form of y = mx + b. (y = 48x + 80).
b. If the number of months is 5 or x = 5, we can solve for the total cost of membership by replacing "x" with "5" in the equation.
![\begin{gathered} y=48x+80 \\ y=48(5)+80 \\ y=240+80 \\ y=320 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/cvd9p34o4fz6f669hdzdgwhda6b04iqjna.png)
The ordered pair is (5, 320).
This ordered pair indicates that the cost for 5-month membership is $320.
c. Since there are 12 months in 1 year, replace "x" in the equation with 12 and then, solve.
![\begin{gathered} y=48x+80 \\ y=48(12)+80 \\ y=576+80 \\ y=656 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/l1uyql4c1h5wyfl0wr2tnzsxsfhochz62u.png)
Therefore, the first year's membership cost is $656.