Maths problem: how to do, thanks?

早晨。(◕‿◕✿)

(i) Write -8 as the difference of two square numbers:
-8 = 1 - 9 = 1² - 3²

(ii) Factorize the expression:
m² - 2m - 8
= m² - 2m + 1² - 3²
= m² - 2m(1) + 1² - 3²
= (m - 1)² - 3²
= [(m - 1) + 3] [(m - 1) - 3]
= (m + 2)(m - 4)