Find the greatest common factor of the given monomials.

-18x^9 and 6x^4

I'm new to factoring and having a hard time figuring it out. I thought it should be -6x^4

Question

Find the greatest common factor of the given monomials.

-18x^9 and 6x^4

I'm new to factoring and having a hard time figuring it out. I thought it should be -6x^4

jhonyy9 · Answer

why minus and why not plus ?

triciaal · Answer

one approach to show the detailed process 

break down each term into its parts then compare the like parts and find the highest common factor for each of the like parts
here term 1 -18 x^9 parts -18 and x^9
here term 2   6 x^4  parts 6 and x^4
like parts -18 and 6 ; x^9 and x^4
what are the factors of -18 and of 6? what is the greatest common factor?
what is the greatest common factor between x^9 and x^4?
now rewrite each term with factors
finally put together each of the greatest factors

with practice you will be able to go through these steps mentally and factor by inspection