Question

(a-b)*(a+b)

Answer 1

\[\begin{aligned}(a - b)(a + b) &=&a(a + b) - b(a + b) \\ & = &a^2 \cancel{+ ab - ab} - b^2 \\ &=&a^2 - b^2 \end{aligned}\]

Answer 2

\[(a-b)\times(a+b)=a (a+b)-b(a+b)\]\[\qquad\qquad\qquad\qquad=a^2+ab-ab-b^2\]
\[\qquad\qquad\qquad\qquad=\]

Answer 3

Ditto!

Answer 4

were thinking the same thing

Answer 5

Whoops! I gave the answer out...

Answer 6

thanks a lot