How do you find the prime factorization of 20?

1 Answer
Apr 8, 2016

Answer:

#20 = 2 xx 2 xx 5#

Explanation:

You can separate out each prime factor in turn as follows:

#20# is divisible by #2# (i.e. even) since its last digit is even.

So divide by #color(blue)(2)# to get #10#.

#10# is divisible by #2# since its last digit is even.

So divide by #color(blue)(2)# to get #5#.

#color(blue)(5)# is prime.

So we can stop and write down #20# as the product of the primes we have found:

#20 = 2 xx 2 xx 5#

This can be written as a factor tree:

#color(white)(00000)20#
#color(white)(0000)"/"color(white)(00)"\"#
#color(white)(000)color(blue)(2)color(white)(000)10#
#color(white)(000000)"/"color(white)(00)"\"#
#color(white)(00000)color(blue)(2)color(white)(0000)color(blue)(5)#