36k²-48k+18 All you can do with that is factor out 6 6(6k²-8k+3) The quadratic in the parentheses will not factor further. So I think you made a typo with the 18 and meant 16. 36k²-48k+16 4(9k²-12k+4) 4(3k-2)(3k-2) 4(3k-2)² If the 18 should have been 16 then your answer is correct. Edwin