How do I solve for b-9-b=-18

Which of the following is true for the relation f(x)=2x^2+1

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.

For what value of (y) is 3^3/3^y =1/9