marya92945 marya92945 22-02-2021 Mathematics contestada Simplify the following expression. (9x2 - 2x + 7) + (4x2 + 7x + 2) A. 13x2 + 5x + 9 B. 5x2 + 5x + 5 C. 13x2 + 9x - 9 D. 13x2 + 9x + 9