Question

How do you multiply `(j + -1k)(j + -1k)`?

Answer 1

See a solution process below:

Explanation:

We can rewrite this expression as:

`(j - k)(j - k) = (j - k)^2`

This is a special case of the quadratic:

`(a -b)^2 = a^2 - 2ab + b^2`

Substituting gives:

`(j - k)^2 = j^2 - 2jk + j^2`