Can someone pls solve for y

Do graduates from uf tend to have a higher income than students at fsu, five years after graduation? a random sample of 100 graduates was taken from both schools. let muf be the population mean salary at uf and let mufsu be the population mean salary at fsu. how should we write the alternative hypothesis?

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?

What is the gcf of 20c^3-5c^4+30c^6