Solve by factoring. x^3-16x=0

Question

I don't quite understand the steps to solving these. Any help?

Answer 1

You can start by factoring out the x:

 

x^3 - 16x = x(x^2-16)   -- > (x^2 - 16) can be further simplified to (x+4)(x-4) 

 

So now x(x^2-16) = x(x+4)(x-4) =0 

 

Our solutions are:

 

x = 0

(x-4) = 0 ---> x = 4

(x+4) = 0 ---> x = -4

 

There are three solutions for x