84 A1 1831 Write The First Five Terms Of The Sequence An = An-1+4, Where A1=20 ?

Write the first five terms of the sequence an = an-1+4, where a1=20 ? - 84 a1 1831

Write the first five terms in the sequence on = an-1 +4, where a1 = 20 Here is the answer, but I do not know how to work the answer to all outputs.
20, 4, 24, 28, 32
4, 24, 44, 64, 84
20, 24, 28, 32, 36
19, 23, 27, 31, 35

Find the zeros of a polynomial f (x) = 2 (x-2) (x +4) ^ 4, and given the large number of individual zero

Here are the 4 answers he gave, but I need to know is how to work with the problem.
2, multiplicity 1, play x-axis and revolves, -4, variety 4, x-axis intersects
2, multiplicity 1, cross-d ", -4, 4 keys several x-axis and revolves
-2, Crosses Multiplicity 1 of the x-axis, 4, 4 buttons several x-axis and revolves
-2, Multiplicity 1, key x-axis and revolves, 4, variety 4, x-axis intersects