Question

How do you factor the expression `x^3+121x`?

Answer 1

You find the common factor in all terms.

Explanation:

We can rewrite the expression as products:

`color(red)(x)*x*x+121*color(red)x`

We can see that both terms are mutiplying `x`, so:

`x(x*x+121)=x(x^2+121)`

Also, if you wish to simplify the number, in this case you're fortunate for being able to do so, as `11^2=121`:

`x^3+121x=x(x^2+11^2)`