Question

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

Answer 1

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

Explanation:

FOIL is a mnemonic to help remember which combinations of terms need to be combined to evaluate the product of two binomials.

In our example, `(x-1)^2 = (x-1)(x-1)` can be evaluated as follows:

`(x-1)(x-1) = overbrace(x * x)^"First" + overbrace(x * (-1))^"Outside" + overbrace((-1)*x)^"Inside" + overbrace((-1) * (-1))^"Last"`

`color(white)((x-1)(x-1)) = x^2-x-x+1`

`color(white)((x-1)(x-1)) = x^2-2x+1`