Question

In the following exercises, factor completely

$5u^4-45u^2$.

Short answer

The factors of the given expression are $5u^2(u-3)(u+3)$.

Step-by-step solution

Step 1. Given and explanation 

We have $5u^4-45u^2$.

The above expression can be solved using the formula,

$a^2-b^2=(a+b)(a-b)$

Step 2. Factorizing the expression. 

We have $5u^4-45u^2$.

Now,

$$\begin{gathered} 5u^4-45u^2 \\ =5u^2(u^2-9) \\ =5u^2(u+3)(u-3) \end{gathered}$$