May I please receive help

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9

This is so hard and it’s for a test

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.