x² + px + q = 0
x² - 6x - 19 = 0
x = 1(-p + √p² - 4q)
2
x = 1(-(-6) + √-(6)² - 4(-19)
2
x = 1(6 + √-36 + 76)
2
x = 1(6 + √40)
2
x = 1(6 + √4 × 2 × 5)
2
x = 1(6 + √4 √2 √5)
2
x = 1(6 + 2 √2 √5)
2
x = 1(6 + 2 √2 √5) x = 1(6 - 2 √2 √5)
2 2
x = 1(8 √2 √5) x = 1(4 √2 √5)
2 2
x = 4(0.5)(1.25) x = 2(0.5)(1.25)
x = 2.5 x = 1.25
