How can you use prime factorization to determine if 738 is evenly divisible by 14?

1 Answer
Apr 27, 2016

See explanation.

Explanation:

It is difficult to divide 738 by 14 without a calculator, but it is easy to see, that:

14=2*7

So if 738 was to divide by 14 it would have to divide by both 2 and 7

It is an even number, so it divides by 2, but it does not divide by 7. We can see this if we write

738=700+38

700 clearly divides by 7 but 38 does not, because it lies between 2 consecutive multiples of 7: 35<38<42.

So because 738 does not divide by 7 it cannot divide by 14.

This example shows that to check if one number divides by the other you can find the prime factorization of the second number and check if the first number divides by all prime factors of the second one.