help please

[dar1125]

Hello, I've forgotten how to do something that I'm sure is quite simple. when you have (x+3)^3 I thought the correct answer to that would be x^3 +27, but it's wrong. Could someone refresh my memory on how to get the correct answer ? thanks

 

[ctelady]

When you have (x+3)^3 I thought the correct answer to that would be x^3 +27, but it's wrong.

(x+3)(x+3) (x+3) FOIL the first pair -->
(x^2 +6x + 9) (x+3) Multiply the trinomial by x, and then by +3
Combine the like terms for your final answer.

 

[dar1125]

Thanks for the help !