Tap the blue circles to see an explanation.
| $$ \begin{aligned}(x+1)(x^2+16)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x^3+16x+x^2+16 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}x^3+x^2+16x+16\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{x+1}\right) $ by each term in $ \left( x^2+16\right) $. $$ \left( \color{blue}{x+1}\right) \cdot \left( x^2+16\right) = x^3+16x+x^2+16 $$ |
| ② | Combine like terms: $$ x^3+x^2+16x+16 = x^3+x^2+16x+16 $$ |