Tap the blue circles to see an explanation.
| $$ \begin{aligned}-(z+1)+2(z-2)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-z-1+2(z-2) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-z-1+2z-4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}z-5\end{aligned} $$ | |
| ① | Remove the parentheses by changing the sign of each term within them. $$ - \left(z+1 \right) = -z-1 $$ |
| ② | Multiply $ \color{blue}{2} $ by $ \left( z-2\right) $ $$ \color{blue}{2} \cdot \left( z-2\right) = 2z-4 $$ |
| ③ | Combine like terms: $$ \color{blue}{-z} \color{red}{-1} + \color{blue}{2z} \color{red}{-4} = \color{blue}{z} \color{red}{-5} $$ |