Question

double check the following rate of change (how much is the price increasing each hour?) rewrite the following.

A babysitter charges a 55 flat booking fee plus 55 for every hour she works, so the total pay y (in
dollars) after x hours is y = 5 + 5x. The graph starts at $5 when x = 0 (the booking fee) and rises $5 for
each additional hour, reaching $40 after 7 hours. So, this graph models shows how total pay increases linearly with time worked and can be used to predict earnings for any number of hours.

Answer 1

There’s a typo in the original. If the babysitter charges a $55 flat booking fee plus $55 per hour, the hourly rate (rate of change) is $55 per hour, not $5.

Corrected rewrite:
- Let x be hours worked and y the total pay in dollars.
- The linear model is y = 55 + 55x.
- At x = 0 the pay is $55 (the booking fee). For each additional hour the pay increases by $55 (the slope).
- After 7 hours: y = 55 + 55·7 = $440.

(If you actually meant $5 flat fee plus $5 per hour, replace every 55 above with 5 and the rate of change would be $5/hour.)