John is going on a trip and the country he is traveling to uses the celsius scale. he is curious about converting celsius temperatures to fahrenheit. john determines 68°f is equivalent to 20°c and 86°f is equivalent to 30°c. which function models the relationship between fahrenheit and celsius?
f=5/9c-512/9
f=9/5c-32
f=9/5c-512/5
f=9/5c+32

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.