May i have the answer to this i ready question

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

Which equation is equivalent to the given expression? -(1/2y+1/4) a. -1/4(1+2y) b. 1/4(2y-1) c. -2(1/4y-1/8) d. 2(1/8-1/4y)

Ahmed plans to add a rectangular sunroom to his house. the sunroom will have a length of 14 feet and a width of 10 feet, and the construction will cost $40 per square foot. how much more would the sunroom cost if it’s width were increased to 12 feet?