Question

In a Northwest Washington County, speeding fines are determined by the formula:F = 8(s-60) + 40where F is the cost, in dollars, of the fine is a person caught driving at a speed of s miles per hour. If a fine comes to $192, how fast was the person speeding?Answer: The person's speed was _____ miles per hour.

Answer 1

Given the formula:

`F=8\mleft(s-60\mright)+40`

where F is the cost, in dollars, of the fine is a person caught driving at a speed of ( s )miles per hour

When F = $192, we will solve the formula to find s

so,

`\begin{gathered} 192=8\mleft(s-60\mright)+40 \\ 192-40=8(s-60) \\ 152=8(s-60) \\ (152)/(8)=s-60 \\ \\ 19=s-60 \\ 19+60=s \\ s=79 \end{gathered}`

So, the answer will be:

The person's speed was 79 miles per hour.​