Final answer:
The work done by F1 is -12.0 J, the work done by F2 is 24.0 J, the work done by F3 is -6.0 J, and the resultant force is 70.0 N. 
Step-by-step explanation:
The calculation of work done by individual forces involves employing the equation: Work = Force * Distance * cos(theta). 
For force F1, the work is computed as 20.0 N * 0.600 m * cos(180°), resulting in -12.0 J. 
Force F2's work is determined as 40.0 N * 0.600 m * cos(0°), yielding 24.0 J. 
Similarly, force F3's work is found to be 10.0 N * 0.600 m * cos(180°), amounting to -6.0 J. 
To establish the resultant force, the vector sum of F1, F2, and F3 is calculated, resulting in a resultant force of 70.0 N. 
Consequently, the work done by the resultant force is expressed as Work = Resultant force * Distance * cos(theta), with the final equation involving the specific value of 70.0 N * 0.600 m * cos(theta). 
This comprehensive approach allows for the determination of work done in a system with multiple forces acting in various directions.