Plz help me with this question

Solve this system of equations using the elimination method?

States might choose to cooperate at the regional or global level for all of the following reasons except (2 points) a.) to gain regional political influence b.) to engage in dispute resolution c.) to assure basic human rights d.) to encourage economic interaction e.) to increase national sovereignty

This is an ap world history question. i am working on a worksheet which has a vent diagram with each circle labeled either us or byzantine economy. the middle is the similarities. can someone explain to me the similarities and especially the differences between the two?