Tap the blue circles to see an explanation.
| $$ \begin{aligned}\frac{3a-3+3bi}{(a+bi)^2+4(a+bi)+1}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{3a-3+3bi}{a^2+2abi+b^2i^2+4a+4bi+1} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{3a-3+3bi}{b^2i^2+2abi+a^2+4bi+4a+1}\end{aligned} $$ | |
| ① | Find $ \left(a+bi\right)^2 $ using formula. $$ (A + B)^2 = \color{blue}{A^2} + 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ a } $ and $ B = \color{red}{ bi }$. $$ \begin{aligned}\left(a+bi\right)^2 = \color{blue}{a^2} +2 \cdot a \cdot bi + \color{red}{\left( bi \right)^2} = a^2+2abi+b^2i^2\end{aligned} $$ |
| ② | Multiply $ \color{blue}{4} $ by $ \left( a+bi\right) $ $$ \color{blue}{4} \cdot \left( a+bi\right) = 4a+4bi $$ |
| ③ | Combine like terms: $$ a^2+2abi+b^2i^2+4a+4bi = b^2i^2+2abi+a^2+4bi+4a $$ |