Me asap with a function percent problem, giving double 12 points! i think my answer might be wrong

Perform the required operations on the following functions given: f(x)= 3-x; g(x)= -2x find g[f(x)]

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

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.