How do you find the greatest common factor of 80, 16?

1 Answer
Nov 1, 2016

The Greatest Common Factor of 80, 16 is 16

Explanation:

Method suggested :

  • Find the prime factors of each number :

80 = 2xx4xx10 = 2xx2xx2xx2xx5 = 2^4xx580=2×4×10=2×2×2×2×5=24×5
16 = 4xx4 = 2xx2xx2xx2 = 2^416=4×4=2×2×2×2=24

  • Find the common prime factors : in this case there's only 2
  • If you have many, take the smaller of the exponents of theses common prime factors and multiply them together to find the GCF, for this example GCF = 2^4 = 16GCF=24=16

Example : Find the GCF of 90, 24

90= 9xx2xx5=3^2xx2^1xx590=9×2×5=32×21×5
24=3xx4=3^1xx2^224=3×4=31×22

  • The common factor primes are 2 and 3
  • The smaller exponents of each are 2^1 and 3^121and31
  • Multiply those and the GCF = 3^1xx2^1=6GCF=31×21=6

I hope that was clear, you can find more in the link below :

Source :
(http://www.coolmath.com/prealgebra/01-gcfs-lcms/02-greatest-common-factors-03)