# Is #9x^2 + 42x + 49# a perfect square trinomial and how do you factor it?

##### 2 Answers

See below

#### Explanation:

We know that

In our case:

If

To verify whether it fits the pattern, we set the first term of the pattern equal to the first term of the given trinomial:

Then we set the last term of the pattern equal to the last term of the given trinomial:

Taking the square root of both we obtain:

We can use this information to check whether the middle term is true:

The middle term is true, therefore, we conclude that the given trinomial is a perfect square.

We can use the left side of the pattern to factor the given trinomial: