What is the greatest common factor of 18, 30, and 45? I come up with 3 as the greatest common factor am I right?
Yes. You're right.
18 = 3*3*2
30 = 5*3*2
45 = 5*3*3
so
3 is the biggest factor that is in all three.
by the way for the smallest common multiple
we need two 3s and one 2 and one 5
3*3*2*5 = 90 (used to get least common denominator
Yes, you are absolutely right! The greatest common factor (GCF) is indeed 3 for the numbers 18, 30, and 45. Let me explain how you can find the GCF using a step-by-step process.
1. Begin by listing the prime factors of each number:
- The prime factors of 18 are 2 and 3 (18 = 2 * 3 * 3).
- The prime factors of 30 are 2, 3, and 5 (30 = 2 * 3 * 5).
- The prime factors of 45 are 3, 3, and 5 (45 = 3 * 3 * 5).
2. Next, identify the factors that appear in each number. In this case, the common factors are 3 and 5. We can ignore the factor 2 because it only appears in the number 18.
3. Lastly, determine the greatest common factor of the numbers by multiplying the common factors. In this case, the greatest common factor is 3 * 5 = 15.
It's important to note that you correctly identified one of the common factors, which is 3. However, you missed the common factor of 5. Therefore, the correct GCF is 15, not 3.