Tap the blue circles to see an explanation.
$$ \begin{aligned}(2w+1)(2w-1)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}4w^2-2w+2w-1 \xlongequal{ } \\[1 em] & \xlongequal{ }4w^2 -\cancel{2w}+ \cancel{2w}-1 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}4w^2-1\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{2w+1}\right) $ by each term in $ \left( 2w-1\right) $. $$ \left( \color{blue}{2w+1}\right) \cdot \left( 2w-1\right) = 4w^2 -\cancel{2w}+ \cancel{2w}-1 $$ |
② | Combine like terms: $$ 4w^2 \, \color{blue}{ -\cancel{2w}} \,+ \, \color{blue}{ \cancel{2w}} \,-1 = 4w^2-1 $$ |