15PTS PLEASE HELP ASAP!
(dont write random answers pls)
look at the pic attached:

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

Can someone me i’m confused. will give brainliest and a whole bunch of points

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15