Tap the blue circles to see an explanation.
| $$ \begin{aligned}(x-8)(x-7)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x^2-7x-8x+56 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}x^2-15x+56\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{x-8}\right) $ by each term in $ \left( x-7\right) $. $$ \left( \color{blue}{x-8}\right) \cdot \left( x-7\right) = x^2-7x-8x+56 $$ |
| ② | Combine like terms: $$ x^2 \color{blue}{-7x} \color{blue}{-8x} +56 = x^2 \color{blue}{-15x} +56 $$ |