1/ Yaster Car Sharing offers a membership plan with a $54 per month...

1/ Yaster Car Sharing offers a membership plan with a $54 per month fee that includes 13 hours of driving each month and charges $9 for each additional hour. Let F(x) be the cost for a month in which a member uses a car for x hours.

Then F(x) is the piecewise function

• F(x)= 54, for 0x 13,
• F(x)=mx+b, for x> 13 for some scalars m and b.

Find b. Round to the nearest whole number.