How do you turn 3.5 into a fraction

Which statement about perfect cubes is true

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.

Which letters from the table represent like terms? a and b b and c a and d b and d