Simplify the expression (x+8)^3

Question

Simplify the following expression:

 

(x+8)^3; and the answer is not x^3+512.

Answer 1

Hi Joshlyn,

 

To answer this question, you have to remember that you can't distribute a power the same way you can distribute multiplication and division. So (x+8)³ is the same as (x+8)(x+8)(x+8).

 

Then you multiply it out, and it looks like

 

x³+8x²+8x²+64x+8x²+64x+512

 

You do this by multiplying each of the numbers in each binomial by each of the other numbers, so first you do x*x*x, then x*x*8, then x*8*x, and so on.

 

Simplified, this looks like

 

x³+32x²+128x+512

 

 

Hope this helped!