What is a variable? A. A variable is something we always know and is represented by a symbol

B. A variable is something we do not know and we use a letter to represent it.

C. A variable is the number in front of the letter in an expression.

B. A variable is something we do not know and we use a letter to represent it.

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

coin flip

non-answer:

choosing

sorry if this isnt what you're looking for i dont really understand the question