If a car has a mass of 670kg and has a driving force of 1200N and a force from resistance of 300N, what is the acceleration of the car? What is the speed of the car after 5 seconds?

The force of resistance should be taken away from the driving force to result in a total force of 900N driving forwards.Then use F=ma, rearranged so that a = F/m, to result in an acceleration of 1.34 m/s^2.
From this acceleration, the speed can be found by taking the 5 seconds and multiplying this by the acceleration in order to find m/s. The answer would be 6.72 m/s.