# How do you factor the expression #x^2+4x-21#?

##### 2 Answers

Mar 6, 2018

#### Answer:

#### Explanation:

To factorise any quadratic polynomial , you could use 2 methods.

Here's the easy one

Let the quadratic polynomial be

▪multiply

The other method is a direct application of quadratic formula.

Mar 6, 2018

#### Answer:

the answer is

#### Explanation:

there's an easier way to find this but only when it's