# How do you factor completely #x^2 - 8x + 16#?

##### 1 Answer

This is a perfect square trinomial, because the first and last terms are perfect squares

#### Explanation:

Method 1:

You can also double check by making sure term b (the middle term) satisfies the equation **only once you have factored, or when you have taken the square root of the first and last term**. We check:

Method 2:

Factor as a regular trinomial of the form

To factor a trinomial of the form ax^2 + bx + c, a = 1#, you must find two numbers that multiply to c and that add to b.

We must find two numbers that multiply to +16 and add to -8. These two numbers are -4 and -4.

So, (x - 4)(x - 4). Since the parentheses repeats itself twice, we can rewrite the expression as

**Practice exercises:**

- Factor the following trinomials using
**method 1**

a)

b)

2 . Factor the following trinomials using **method 2**

a)

b)

c)

d)

3 . Find the value of **perfect square trinomials**

a)

b)

Good luck!