Question

how do you write the product (a-b)^2

Answer 1

$(a-b)^2=(a-b)\cdot(a-b)$

using distributive property:

$(a-b)\cdot(a-b)=a^2-ab-ba+b^2$

Add like terms:

$a^2-ab-ba+b^2=a^2-2ab+b^2$