What is the general rule for (a-b) squared? Eplain, don't just tell me.
(a - b)^2
= (a - b)(a - b)
= a(a - b) - b(a - b)
= a^2 - ab - ba + b^2
Remember, ab is the same as ba
= a^2 - 2ab + b^2 ✌
+150 
