Question

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

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/inconsistency in the original: the text says “55” but the equation given is y = 5 + 5x and the numbers that follow (starting at $5 and reaching $40 after 7 hours) match the $5 values. Assuming the correct numbers are $5 and $5, here is a corrected rewrite with the rate of change added:

A babysitter charges a $5 flat booking fee plus $5 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 increases by $5 for each additional hour; in other words, the rate of change (slope) is $5 per hour. After 7 hours the total pay is y = 5 + 5·7 = $40. This linear model shows how total pay increases at a constant rate with time worked and can be used to predict earnings for any number of hours.

If you meant $55 instead of $5, the correct equation would be y = 55 + 55x, the rate of change would be $55 per hour, and after 7 hours y = 55 + 55·7 = $440.