What is the GCF of 75 and 90?

1 Answer
Oct 15, 2016

#15#

Explanation:

The simplest way to find the Greatest Common Factor is as follows:

  • Find one Common Factor
  • Divide by that factor
  • Look for a Common Factor in the new set of numbers
  • Divide by that factor
  • Repeat until you arrive at a dead end
  • Gather all of the factors that you used and multiply them together.
  • You should have the GCF now.

Your Question:
GCF of #75# and #90#

  • They have a common factor of #5#
  • #75/5# and #90/5# equal #15# and #18#
  • #15# and #18# have Common Factor of #3#
  • #15/3# and #18/3# equal #5# and #6#
  • #5# and #6# do not have any Common Factors
  • We divided by #5# and #3#.
  • #5*3=15#