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

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Answer 1 · 2018-03-14T14:51:27

$x^2-2x+1$

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:

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

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