A toy car is pulled along a straight track by two forces: to the right and to the right

PHYSICS · Subjective · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics

Problem

A toy car is pulled along a straight track by two forces:

7\,\text{N}

to the right and

3\,\text{N}

to the right. What single additional horizontal force (state magnitude and direction) will keep the car from accelerating?