3x² + 10x + 6 = 0 x = -(10) ± √((10)² - 4(3)(6)) 2(3) x = -10 ± √(100 - 72) 6 x = -10 ± √(28) 6 x = -10 ± 2√(7) 6 x = -5 ± √(7) 3 x = -1²/₃ ± ¹/₃√(7)
5x² - 6x + 1 = 0 x = -(-6) ± √((-6)² - 4(5)(1)) 2(5) x = 6 ± √(36 - 20) 10 x = 6 ± √(16) 10 x = 6 ± 4 10 x = 3 ± 2 5 x = 3 + 2 or x = 3 - 2 5 5 x = 5 or x = -1 5 5 x = 1 or x = -0.2
2x² - 7x - 15 = 0 x = -(-7) ± √((-7)² - 4(2)(-15)) 2(2) x = 7 ± √(49 + 120) 4 x = 7 ± √(169) 4 x = 7 ± 13 4 x = 7 + 13 or x = 7 - 13 4 4 x = 20 or x = 6 4 4 x = 5 or x = 1.5
x² + 4x + 1 = 0 x = -(4) ± √((4)² - 4(1)(1)) 2(1) x = -4 ± √(16 - 4) 2 x = -4 ± √(12) 2 x = -4 ± 2√(3) 2 x = -2 ± √(3) 2 x = -1 ± ¹/₂√(3) x = -1 + ¹/₂√(3) or x = -1 - ¹/₂√(3)
