27x3+54x2+198x-73=(3x-1)(9x2+21x+73).
Using synthetic division for the zero x=1/3:
1/3 | 27 54 198 | -73
27 9 21 | 73
27 63 219 | 0 = 3(9x2+21x+73).
9x2+21x+73=0 can be solved using the quadratic formula.
x=(-21±√(441-2628))/18=(-21±27i√3)/18=(-7±9i√3)/6.
Zeroes are 1/3, (-7+9√3)/6, (-7-9√3)/6.