Question

Factorise x^2 - 1
Please help

Answer 1

`(x+1)(x-1)`

Explanation:

Let's factor:
`x^2-1`

`x^2-1`

The middle number is 0 and the last number is -1.

Factoring means we want something like

( x + _ )( x + _ )

Which numbers go in the blanks?

We need two numbers that…

• Add together to get 0
• Multiply together to get -1

Can you think of the two numbers?

Try 1 and -1:

`1 + (-1) = 0\\1*(-1) = -1`

Fill in the blanks in

(x+_)(x+_)

with 1 and -1 to get...

(x+1)(x-1)

Answer 2

(x−1)(x+1)

Explanation: