Find the LCM by factoring.
-12, 7
A)19
B)42
C)12
D)84

Question

Quizplus · Accepted Answer

The prime factorization of 12 is 2^2*3
The prime factorization of 7 is 7
The LCM will have all the prime factors of both numbers, with the highest exponent of each prime factor. 
Therefore, LCM = 2^2*3*7 = 84. To find the LCM by factoring, we need to factor each number into its prime factors:
12 = 2^2 * 3
7 is already prime.
Then we take the highest power of each prime factor: 
2^2 *3 * 7 = 84 
Therefore, the LCM of 12 and 7 is 84. The correct answer is D.

Find the LCM by Factoring