Answer:
Given equations:
To multiply 1 and 2;
[tex]{ \tt{a \times b = (x + y)(x - y)}} \\ = { \tt{(x.x) + (x. - y) + (y.x) + (y. - y)}} \\ = { \tt{ {x}^{2} - xy + xy - {y}^{2} }} \\ = { \tt{ {x}^{2} - {y}^{2} }}[/tex]
