The rate of change if the health club charges a $35 one-time sign-up fee and a monthly membership fee of $39 per month is $39.
Total charge = 35 + 39x
If x = 1 month
Total charge = 35 + 39x
= 35 + 39
= $74
If x = 2 months
Total charge = 35 + 39x
= 35 + 39(2)
= 35 + 78
= $113
Rate of change = $113 - $74
= $39
Therefore, the rate of change is $39
Learn more about rate of change:
https://brainly.com/question/8728504
#SPJ1