My old Holden’s speedometer was not calibrated correctly it displayed70 km/h when its true speed was 55 km/h, it also displayed 40 km/h whenits true speed was 32 km/h.

(a) Using the variables T for true speed and D for displayed speed, determine the linear equation that could relate the displayed and true speeds.

(b) When the speedometer displays 100 km/h how fast am I actually going?

(c) When I am going 100 km/h what speed does the speedometer display?