Question 311468
12x^2 + 21x + 6 = 0
.
x1, x2 the roots are to be found out 

x1 = -21 + sqrt(21^2-4*12*6) /2*12
x1=-21+sqrt(441-288) / 24
x1= -0.359
..
x2 = -21-sqrt(441-288) / 24
= -1.390