To factorize the given function you:
You can find if the equation correspond to a perfect square trinomial by knowing that the numbers 16x^2 and 25 are perfect squares (numbers that have a perfect sqare root) and the term 40x is equal to 2 times 4x*5. and 5.
Then,
The equation follows the next general form to a perfect square trinomial:
Then, you can rewrite the given equation as:
And knowing that:
You get that the given equation is equal to: