Q&A for How to Find the Greatest Common Factor

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What level of questions should I make for a test? Should I make the test easy, medium or hard?

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It depends upon your knowledge of your students. If you see that your students are very competitive and clever, you can make the test hard, so as to challenge their knowledge about the subject. If your students are beginners and have a lot to learn yet, making it easier will encourage them to keep learning more.

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What's the greatest common factor of 4x^3y, 8x^2y^3, xy^3z^5?

Donagan

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The three terms are: 4x³y, 8x²y³, and xy³z^5. First, in terms of numerical coefficients, the lowest coefficient in the three terms is 1. The lowest x exponent is 1. The lowest y exponent is also 1. There is no z in two of the terms (so z is not a common factor). That means the greatest common factor among the three terms is 1xy (or xy).

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What is the use of prime numbers in our lives?

Donagan

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The average person is never likely to use prime numbers. They do have certain applications within science and mathematics.

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What is the greatest common factor for 16 and 28?

Donagan

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16 = 2 x 2 x 2 x 2. 28 = 2 x 2 x 7. The greatest factor common to both is 2 x 2 = 4.

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Is the number one a prime factor?

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One is not a prime, but it is commonly confused with one. One is actually referred to as a unit.

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What happens if there's more than one common prime factor?

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Finding the greatest common factor means selecting the largest one.

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Should I use the same method for larger numbers?

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No. Unless you can do the prime factorization in your head, Euclid's method is much faster and easier.

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What is the greatest common factor of 20 and 40?

Donagan

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20.

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What is greatest common factor of 2x2 - 7x - 15?

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There is no term -- other than 1 -- that divides evenly into all three of those terms. So 1 is the GCF.

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What is the greatest common factor of 135 and 10?

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5 is the GCF. The factors of 10 are 1, 2, 5 and 10. The factors of 135 are 1, 3, 5, 27, 45 and 135. The largest number common to both lists is 5.

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Find the greatest common factor of 8 and 12

I_l1ke_gam3s

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The factors of 8 are 1, 2, 4, and 8. The factors of 12 are 1, 2, 3, 4, 6, and 12. 4 is the largest number that divides evenly into both 8 and 12. That makes 4 the GCF.

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What is the GCF of 45 and 63?

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It's 9, the greatest number that divides evenly into 45 and 63. To solve this, break the numbers into their factors: 45 = (3)(3)(5), and 63 = (3)(3)(7). So the factors common to both numbers are 3 and 3, whose product is 9.

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What is the greatest common factor of 24 and 54?

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The answer would be 6.

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What is the GCF of 40 and 100?

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The answer would be 20.

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What is the answer for 5 and 10 greatest common factor?

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The answer would be 5.

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Is GFC (greatest common factor) the same as HFC (highest common factor?)

Community Answer

Yes, the two are the same. It may also be known as the greatest common divisor (GCD). All three mean the same thing.

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What is the GCF of 20, 40, 60?

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The GCF of those numbers is 20. This is because all of them are divisible by 20 and 20 is one of the numbers, so you cannot use a number higher than 20 or else it wouldn’t be a factor of it.

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What do GCF and LCM mean?

Community Answer

Greatest common factor (GCF), this refers to the largest number that can be “fit” inside a set of numbers. Lowest Common Multiple (LCM) is the smallest number that can “fit” inside a set of numbers.

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