# expansion

• Dec 10th 2008, 09:44 AM
hmmmm
expansion
how would you expand (a^x+b)^y?
sorry if this is in wrong place but i wasnt sure where to put it.
thanks for any help.
• Dec 10th 2008, 09:49 AM
Jhevon
Quote:

Originally Posted by hmmmm
how would you expand (a^x+b)^y?
sorry if this is in wrong place but i wasnt sure where to put it.
thanks for any help.

look up binomial expansion

$(x + y)^n = \sum_{k = 0}^{n} {n \choose k}x^{n - k}y^k$
• Dec 10th 2008, 09:53 AM
hmmmm
thanks
thanks very much but what happens if the x has a power that isnt 1?
• Dec 10th 2008, 01:36 PM
Jhevon
Quote:

Originally Posted by hmmmm
thanks very much but what happens if the x has a power that isnt 1?

say we write x as $a^x$ in the above formula:

$(a^x + y)^n = \sum_{k = 0}^{n} {n \choose k}(a^x)^{n - k}y^k$