Concept:This problem involves adding and subtracting polynomials by combining like terms.Explanation:First, write the expressions: p=3x2−6x−4, q=3+x−2x2, r=−4x+x2+9.Compute (p−q)+r. Substitute the polynomials:(3x2−6x−4)−(3+x−2x2)+(−4x+x2+9).Remove brackets carefully. The minus sign before q changes each term's sign:3x2−6x−4−3−x+2x2−4x+x2+9.Now group like terms:x2 terms: 3x2+2x2+x2=6x2.x terms: −6x−x−4x=−11x.Constants: −4−3+9=2.So, (p−q)+r=6x2−11x+2.Answer:6x2−11x+2 (Option D).