How do i figure out input and output

What is the 12th term of b(n)=-4-2(n-1)

Sandy is ordering bread rolls for her party,she wants 3/5 of the rolls to be whole wheat. what other factions can represent part of the rolls that will be whole wheat? shade the models to show your work.

Find the equation of the line with slope =8 and passing through (6,53) write your equation in the form y=mx+b