Add the forces (net force or resultant force)

Four forces act on a box along one line. A force to the right is a plus number, a force to the left a minus number. You will make the program add them to find the net force, say which way the box speeds up, and find the biggest single force. Then it draws every force as an arrow.

The idea. The net force is the sum of the forces with their signs. If it is zero, the forces are balanced.

Your tasks.

1. Work out net, the sum of the forces.
2. Set way to "right", "left" or "balanced".
3. Find biggest, the size of the largest single force, ignoring its direction.