Describe the error(s) that occurred and show the correct solution.

Step-by-step explanation:

we have

step 1

Eliminate the parenthesis

The symbol of the term 3x is incorrect, must be positive instead of negative

so

Group terms that contain the same variable

Combine like terms

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