Question

a gym membership charges a monthly fee plus an additional cost for each personal training session. the total cost, c, in dollars can be represented by the equation c = 2.25s + 15, where s is the number of personal training sessions. which of the following ordered pairs (s, c) would not be on the graph representing this relationship? a.(2,19.5) b.(0,15) c.(4,24) d.(6,28.5)

Explanation:

Step1: Substitute values of (s, c) into equation

For an ordered - pair (s, c) to be on the graph of the equation \(c = 2.25s+\text{(some constant)}\), when we substitute the value of \(s\) into the equation, we should get the corresponding value of \(c\).

Step2: Check option A

For the ordered - pair \((2,7.5)\), substitute \(s = 2\) into \(c = 2.25s+\text{(constant)}\). Let's assume the constant is \(b\). Then \(c=2.25\times2 + b=4.5 + b\). If \(b = 3\), \(c = 7.5\).

Step3: Check option B

For the ordered - pair \((0,3)\), substitute \(s = 0\) into \(c = 2.25s + b\). We get \(c=b\). If \(b = 3\), this is a valid point.

Step4: Check option C

For the ordered - pair \((4,12)\), substitute \(s = 4\) into \(c = 2.25s + b\). Then \(c=2.25\times4 + b=9 + b\). If \(b = 3\), \(c = 12\).

Step5: Check option D

For the ordered - pair \((6,21.5)\), substitute \(s = 6\) into \(c = 2.25s + b\). Then \(c=2.25\times6 + b=13.5 + b\). If \(b = 3\), \(c=16.5
eq21.5\).

Answer:

D. \((6,21.5)\)