zaid2820 zaid2820 20-04-2022 Mathematics contestada Which of the following would best be solved using completing the square? A) 2x^3 - 12x^2 + 5x - 30 = 0 B)5x^2 + 7x = 12 C) x^2 = 81 D) x^2 + 4x - 21 = 0