Factor completely:

x³ - 9x

x(x+3)(x-3)

Step-by-step explanation:

Factor out common term x

=x(x^2-9)

Factor x^2-9;

(x+3)(x-3)

=x(x+3)(x-3)

x(x + 3)(x - 3)

Step-by-step explanation:

What we're given is a difference of squares multiplied by x.  If we start by factoring x out, we can simply expand the binomial:

x³ - 9x

= x(x² - 9)

= x(x + 3)(x - 3)

Any time you see an expression in the format a² - b², that is called a difference of squares, and can always be expanded out to (a + b)(a - b).  In this case, a is x, and b is 3.

4sqrt5

step-by-step explanation:

the base has dimensions of 8 x 4, so the diagonal is 64 + 16 square rooted or 4sqrt5.