Can anyone explain to me what I did wrong here? Thanks!

Lassify the function as linear or quadratic and identify the quadratic, linear, and constant terms. f(x) = (3x + 2)(−6x − 3) linear function; linear term: −21x; constant term: −6 linear function; linear term: −18x2; constant term: −6 quadratic function; quadratic term: 6x2; linear term: 24x; constant term: −6 quadratic function; quadratic term: −18x2; linear term: −21x; constant term: −6

Need on this geometry question. explain how you did it.

Standard deviation of 19,29,21,22,23