How do you find the GCF of 21, 45?

Answer 1

GCF of 21 and 45 is 3

Consider that #45=9(5)# and #21=3(7)#
Since #3^2=9# we can say
#45=3^2(5)# Therefore 45 is divisible by 3

Since 3 is the only common factor between 45 and 21 in their prime factorization, it is the greatest common factor of 45 and 21. Furthermore, since both 45 and 21 are divisible by 3, it is a common factor.

Alternatively, GCF (21,45)=3.

An additional technique

Since #45=21(2)+3#

Next, we may state

#45-=3 mod 21#

Given that 3 is prime, GCF (21,45)= 3.

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Answer 2

To find the greatest common factor (GCF) of 21 and 45, you can use the method of prime factorization.

Step 1: Find the prime factorization of each number. 21 = 3 * 7 45 = 3 * 3 * 5

Step 2: Identify the common prime factors. The common prime factor is 3.

Step 3: Multiply the common prime factors. GCF = 3

So, the greatest common factor of 21 and 45 is 3.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

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