The difference between number 20 and its opposite is what percentage of 200? (if you do not remember: opposite of 15 is −15; opposite of −7 is 7.)

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.