Question

PLEASE HELP ME WITH THIS!! Question 15

Answer 1

I hope this helps you

Answer 2

Hi Zazie,

it's actually not too difficult. The basic process is to take the sets of two numbers, write out the factors for each, circle the factors that they have in common (that's the "common factor" part of GCF), and then pick the largest factor that they have in common.

It's easiest to see this by way of example (using your homework... ;-)

The way to easily set this up is to list the numbers in the left hand column and then write out all the factors in a row. Then, circle all of the factors that the two have in common. Multiply all of the factors that they have in common to figure out the greatest common factor (GCF):

4 = 2 x 2
8 = 2 x 2 x 2

In this case, 4 and 8 each have two sets of "2" in common, so the greatest common factor would equal 2 x 2 or 4. This makes sense since 4 x 1 = 4 and 4 x 2 = 8. So you would put this number set in the "GCF of 4" column.

6 = 2 x 3
10 = 2 x 5

In this case, the only factor that 6 and 10 have in common is the number 2. You can't pick 3 since it is a factor only for 6, and you can pick 5 since it is a factor only for 10. So in this case you would put this set of numbers in the "GCF of 2" column.

8 = 2 x 2 x 2
12 = 2 x 2 x 3

Here, 8 and 12 both share two sets of 2's, so the GCF = 2 x 2 = 4. Put it in the "GCF of 4" column.

You can follow this pattern for the remaining sets of numbers:

10 = 2 x 5
12 = 2 x 2 x 3

20 = 2 x 2 x 5
24 = 2 x 2 x 2 x 3

14 = ???
20 = ???

So, the trick is to be able to factor out each number, then circle the factors that the two numbers have in common, then multiply those factors together to determine the greatest common factor.

Hope this helps.

Good luck!