I need to get a tutor.....

[Guest]

My brain is not good at this I guess.

Any help with:

3a^2 + 27ab + 54b^2

 

[tkhunny]

3a^2 + 27ab + 54b^2

You really have to provide a problem statement. Factor?

Again, FIRST remove the GCF of all three terms if it is other than unity (1).

Since you probably don't know your 18-times-tables , this one may not be obvious.

3a^2 + 27ab + 54b^2 = 3(a^2 + 9ab + 18b^2)

Now, you need factors of 18 that add up to 9. Everything is positive, so there is no subtraction to complicate things.

1*18 =18 --> 1+18=19 -- Nope.
2*9 = 18 --> 2+9 = 11 -- Nope.
3*6 = 18 --> 3+6 = 9 -- Yes!!!

3a^2 + 27ab + 54b^2 = 3(a^2 + 9ab + 18b^2) = 3(a+3b)(a+6b)

 

[Guest]

oops

yes, this is to factor completely. I am always working on all this when I am tired. Sorry, and thanks so much!