GCF of 4 and 5

Find the Greatest Common Factor (GCF) of 4 and 5 with a complete step-by-step solution. The GCF is the largest number that divides both numbers without leaving a remainder.

Answer: GCF(4, 5) = 1

Step-by-Step Solution

Step 1 Find the Factors of 4

To find the GCF of 4 and 5, we first need to find all factors of each number.

The factors of 4 are numbers that divide 4 evenly:

1 × 4 = 4, 2 × 2 = 4

Factors of 4: 1, 2, 4

Step 2 Find the Factors of 5

Now we find all factors of 5:

1 × 5 = 5

Factors of 5: 1, 5

Step 3 Find the Common Factors

The common factors are numbers that appear in both lists:

Factors of 4: 1, 2, 4

Factors of 5: 1, 5

Common factors: 1

The Greatest Common Factor is the largest of these: 1

Step 4 Prime Factorization Method

We can also find the GCF using prime factorization:

4 = 2^2

5 = 5

Take the common prime factors with the lowest powers:

GCF = 1 = 1

Step 5 Euclidean Algorithm

The Euclidean algorithm is a fast way to find the GCF using repeated division:

5 = 1 × 4 + 1

4 = 4 × 1 + 0

When the remainder is 0, the GCF is the last divisor: 1

Step 6 Final Answer

GCF(4, 5) = 1

GCF of 4 and 5

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