# How do you write the fraction #9/21# in simplest form?

##### 2 Answers

Nov 28, 2016

#### Answer:

#### Explanation:

Nov 28, 2016

#### Answer:

#### Explanation:

We have to find a

#color(blue)"common factor"# that will divide into both 9 and 21 and reduce the fraction.In this case the lowest common factor is

#color(red)(3)#

#rArr9/21=(9÷3)/(21÷3)=3/7# This is usually written as shown below.

#9/21=cancel(9)^3/cancel(21)^7=3/7larrcolor(red)" in simplest form"# This process is called

#color(blue)"cancelling"# A fraction is in

#color(red)"simplest form"# when no other factor apart from 1 will divide into the numerator/denominator.