Tap the blue circles to see an explanation.
| $$ \begin{aligned}(3s-2t)(2s-3t)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}6s^2-9st-4st+6t^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}6s^2-13st+6t^2\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{3s-2t}\right) $ by each term in $ \left( 2s-3t\right) $. $$ \left( \color{blue}{3s-2t}\right) \cdot \left( 2s-3t\right) = 6s^2-9st-4st+6t^2 $$ |
| ② | Combine like terms: $$ 6s^2 \color{blue}{-9st} \color{blue}{-4st} +6t^2 = 6s^2 \color{blue}{-13st} +6t^2 $$ |