Answer:
14
Explanation:
The greatest number that divides 42, 70, and 84 exactly is their greatest common factor.
Factors of 42 = 1, 2, 3, 6, 7, 14, 21, 42
Factors of 70 = 1, 2, 5, 7, 10, 14, 35, 70
Factors of 84 = 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
The GCF of 42, 70, and 84 is 14.
The greatest number that divides 42, 70, and 84 is 14.
What is GCF?
The biggest positive integer that divides evenly into all the numbers with no remainder is the greatest common factor (GCF, GCD, or HCF) of a set of whole numbers. For instance, the GCF is equal to 6 for the set of numbers 18, 30, and 42.
How do I get the GCF of something?
The greatest common factor among numbers can be discovered in a number of ways.
Factoring:
List each number's factors in order to calculate the GCF by factoring. The factors that evenly divide into the number with no remainder are known as whole numbers. The GCF is the largest number that appears on each list of common factors for each number.
Example: Find the GCF of 18 and 27
The factors of 18 are 1, 2, 3, 6, 9, 18.
The factors of 27 are 1, 3, 9, 27.
The common factors of 18 and 27 are 1, 3 and 9.
The greatest common factor of 18 and 27 is 9.
Prime Factorization:
List all of each number's prime factors to determine the GCF by prime factorization. List the prime factors that each of the original numbers has in common. Include the most instances of each prime factor that each original number has in common. To find the GCF, multiply these by one another.
You'll observe that the prime factorization approach may be simpler than straight factoring as numbers grow larger.
Example: Find the GCF (18, 27)
The prime factorization of 18 is 2 x 3 x 3 = 18.
The prime factorization of 27 is 3 x 3 x 3 = 27.
The occurrences of common prime factors of 18 and 27 are 3 and 3.
So the greatest common factor of 18 and 27 is 3 x 3 = 9.
There is another method but it focuses on more complex numbers.
Hope this helps!