Question

(x + y)(x - y)
i got as an answer x^2-xy?

Answer 1

you almost had it right just change -xy to -y^2

Answer 2

(x+y)(x-y) = x^2-y^2

Answer 3

x^2-xy+yx-y^2
x^2-y^2

Answer 4

Another helpful rule...\[(a+b)(a-b)=a^{2}-b^{2}\]
This is called the difference of squares formula