1.
57= 3*19
Because 3 and 19 are both prime, that is the prime factorization.
Final answer: 3*19
2.
54= 2*27
2 is prime but 27 can still be factored.
54=2*3*9
Again, 9 can still be factored.
54=2*3*3*3
2 and 3 cannot be further factored so that is the prime factorization.
Final answer: 2*3*3*3