To cancel the fraction 19/16 to get the answer 9/4, you need to find a common factor that can be divided from both the numerator and the denominator.

The factors of 19 are 1 and 19. The factors of 16 are 1, 2, 4, 8, and 16.

Since there are no common factors between 19 and 16, the fraction 19/16 cannot be canceled to get the answer 9/4.