All of the water or water vapor on earth makes up the cryosphere hydrosphere biosphere atmosphere

How do you find principle and simple interest

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.

Can someone me out here and the tell me the greatest common factor