Subject: math help

how do you figure out what the greater common factor is?

The standard way of finding the greatest common divisor (gcd) and the least common multiple (lcm) of two numbers is to first look at their prime factorizations. To determine the gcd look for the largest power of each prime that is common to both of the numbers; to determine the lcm look for the largest power of each prime that appears in at least one of the numbers. For example:

Find the gcd and lcm of 60 and 126

60 = 2x2x3x5,  126 = 2x3x3x7

the gcd is 2x3 = 6 (the primes 2 & 3 appear in both of the numbers)

the lcm is 2x2x3x3x5x7 = 1260 (the primes 2, 3, 5 & 7 appear in at least one of the numbers).

Cheers,
Penny