Question

How do you multiply `(x - 1)^2`?

Answer 1

`x^2-2x+1`

Explanation:

This is a fixed identity, these types of expressions, knowing the theory behind them, can be multiplied easily without any calculations.

For example, let's say you have the expression `(x+y)^2`
It becomes: `x^2+2xy+y^2`

If you have `(x-y)^2`
It becomes: `x^2-2xy+y^2`

You can see the pattern, you can learn it by heart, it is always the same in these cases.

But to explain you why the result is what it is:

`(x-1)^2`
`(x-1)*(x-1)`
`x*x-1*x-1*x-1*(-1)`
`x^2-x-x+1`
`x^2-2x+1`