Which algebraic expression is equivalent to the expression below? (3x + 12) + 8x a. (3x + 8x) + 12 b. (3x - 8x) + 12 c. 23x d. (3x + 12x) + 8

divide by 5

step-by-step explanation:

60/5 = 12

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