Please help me with these math problems (3) . I really need help . Multiple choice don't comment random for points please

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

Two lines that do not intersect are skew. always sometimes or never

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.