Determine the net force acting on the object (represented by the solid circle) in this diagram.

100 n to the right

200 n to the left

300 n to the left

400 n to the right

I'd go with the last one. To find the net force we have to add both values (if they're acting in opposite directions). If the forces are acting in the same direction, the net force is 0.
In this case, the two forces are acting in the opposite directions, so we ADD the 300 to the 100 and we get 400. And, the force is to the RIGHT.

Step-by-step explanation: