How would you rewrite the expression 6x+18x2 by factoring out the GCF?(1 point) Responses 6x (1x+3x) 6 x left parenthesis 1 x plus 3 x right parenthesis 6x (1+3x) 6 x left parenthesis 1 plus 3 x right parenthesis 3x (2+6x) 3 x left parenthesis 2 plus 6 x right parenthesis 6x (1−6x)