Question

Systems in nature tend to undergo changes toward___? Explain your answer.

Answer 1

I think the answer is systems tend to undergo changes towards lower energy and higher entropy. 
Usually the point of chemical reactions is to go from a state of higher energy to lower energy (it is possible for reactions to go from lower to higher energy though as in the case of endothermic reactions). 
As for entropy, usually it requires energy to lower the entropy of a system since entropy can be thought of as the relative disorder of the system.  If you go from a state of higher disorder to lower disorder work usually needs to be done.
This trend can be shown in the equation ΔG=ΔH-TΔs:
ΔG stands for Gibbs free energy
ΔH stands for change in enthalpy
ΔS stands for change in entropy
T stands for temperature
when ever ΔG is negative the reaction is spontaneous which means that it is favored.  As you can see ΔG is negative at any temperature when ΔH is negative and ΔS is positive showing that going to a lower energy state and raising the entropy is usually favored in nature.

I hope this helps.  Let me know if anything is unclear or if you need further explanation.