Jim plans to install wallpaper on the walls of his room. He calculated that he needs 90 square yards of wallpaper. The home improvement store sells wallpaper in square feet.
Which equation can Jim use to find how many square feet of wallpaper he needs to
buy?

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

id

step-by-step explanation:

idk

idk

i know the way

and

idk