10. Use the quadratic formula to solve each equation. Express your answers as exact roots. a) 4x² - 5x-6=0 b) 4x² - 12x +9=0 2x² + 9x +3=0 d) 9x² - 17x+3=0 e) 5x² + 7x-3=0 f) 16x² + 40x+25=0​