Resultant force?????

The drag on the athlete is 42N,the force of the wind is 21N and the force of her muscles is 84N,what is the resultant force and give its direction?
how do i work this out???? Help please

call every force that's helping the athlete move forward positive (so her muscles and if the wind is a tailwind) and every force working against her negative (the drag and the wind if it's a headwind) then add them up.
if the wind is a tailwind:
+84N +21N -42N = +63N
63N in a positive or forward direction

if the wind is a headwind:
+84N -21N -42N = +21N
21N in a positive or forward direction