If the quadratic formula is used to find the roots of the equation x^2-6x-19=0, the correct roots are ?

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

20000 as first it increases by 2500 then by 5000 so next it will increase by 10000