Answer
$F_{net}=(285N)i^{\wedge}-(115N)j^{\wedge}$
Work Step by Step
The net force on Tarzan is the sum of the two forces tension in the vine and the weight of the Tarzan:
$F_{net}=T+W$
We plugin the known values to obtain:
$F_{net}=(285N)i^{\wedge}+(705N)j^{\wedge}-(820N)j^{\wedge}$ (the negative sign shows that weight is directed downward)
$F_{net}=(285N)i^{\wedge}-(115N)j^{\wedge}$
