The frictional force would be horizontal. If the 35.0 N force is also horizontal, those 2 forces would be in opposite directions. That would simplify the calculation. Since no mention is made of any angle, it is unlikely that the 35.0 N force is not horizontal.
Assuming that the 35.0 N force is horizontal, the net force is
35.0
N
−
2.90
N
=
32.1
N
.
