I don’t get it also I need it as a fraction and percent

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.

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9

How many grams the dog will eat in 3 days?