Algebra

Thanks a lot praom but I am sorry I have not yet started using this formula. The site and the page I am refering to is

http://www.themathpage.com/alg/difference-two-squares-2.htm

If you have a look you will notice that I have not yet been taught how to use the formula you mentioned above.

So far I have understood everything the site taught but I got hopelessly stuck at this equation and can not progress further:(

I just don't understand where the negative signs came from in this equation

a^5 + b^5= (a + b)(a^4 - a^3b + a^2b^2 - ab^3 + b^4)

When I multiply (a+b)with the rest I see I get a^5 + b^5 but I don't understand how they got (a^4 - a^3b + a^2b^2 - ab^3 + b^4)after taking out (a+b) as the common factor.

Please help me I am really confused.

Hugs
Autumn

Hi,

It seems the only person helping me so far Praom (hugs) is offline ... any other sweet soul out there that could help me understand how they arrived at the above while factorising?

I know when I multiply (a+b) with the rest I will get a^5+b^5 but how did they get

a^5 + b^5= (a + b)(a^4 - a^3b + a^2b^2 - ab^3 + b^4)

in the first place:(

anyone?:(

Just apply same formula:

a^2 - b^2= (a + b)(a - b)
Right?

similarly
a^3 -b^3= (a + b)(a^2 - ab + b^2)

[Note:a^3 - b^3= (a+b)(b^(3-3)*a^(3-1) - b^(3-2)*a^(3-2) + b^(3-1)*a^(3-3))]

If its a^n + b^n then all terms will be positive
If a^n - b^n then alternative terms will be negative

Apply the power 3 to n.

Hope u understood..

with regards,
praom2104

yes I did.

Thanks a lot.
mwah mwah mwah. hugs cuddles God bless ya

Love
Autumn