【 】Factors of 21 ||What are the Factors of 21? ||Factor Pairs of 21


Factors of 21 ||What are the Factors of 21?








Today we are going to find out the factors of 21 in just few steps.






              Step-1:


◆The numbers that can divide 21 without remainder are called 21's factors.


◆Rule-1: N's factor is the number that can divide N without remainder.


◆Notice that the factors always includes 1 and itself.




             Step-2:

Notice that the factors always includes 1 and itself.

So,the factors of 21 are 1, ............21.


●A simple way is to find what pairs of numbers multiply to get 21.



●21 = 1× 21



21 is divisible by 1 and 21 without any remainder.So,1 and 21 are the two factors of 21.


Proofs:


●21/1=21

●21/21=1




           Step-3:

Already we have gotten two factors of 21 which are 1 and 21.In this step we will find out other factors of 21 by applying the following rule.



◆N's factor is the number that can divide N without remainder.


So,the numbers that can divide 21 without remainder are called 21's factors.


●A simple way is to find what pairs of numbers multiply to get 21.



●21=3 ×7






Proofs:


●21/3=7

●21/7=3







21 is divisible by 3,7 without any remainder.


So,the total number of positive factors of 21 (including 1 and itself) are 1,3,7and 21.


            Step-4

●We have to keep in mind that the factors of an integer include both the positive and negative integers.


So, the factors of 21  include negative numbers or integers. Hence, all the positive factors of 21 can be easily converted to negative numbers .The negative factors of 21 are given below:

-1,-3,-7and -21.



 Look carefully:

(◆Negative times  Negative=Positive) 


◆21= -1 × -21

◆21= -3 × -7


So,the total number of  negative factors of 21  are -1,  -3, -7,  and -21.

●How many factors does the number 21 have?

Ans:21 has 8 factors totally.The number 21 has 4 positive factors and 4 negative factors.


Course:How to Find Factors of Numbers

◆Factor Pairs of 21

Here are the factor pairs of 21.

●A simple way is to find what pairs of numbers multiply to get 21.

◆21=1×21

◆24=3 ×7


Look carefully:



◆21=-1× -21

◆24= -3 × -7

 The integer 21 has 4 factor pairs.These are given below:
1×21,3× 7 ,-1×-21,-3×-7




Continue





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