Tap the blue circles to see an explanation.
$$ \begin{aligned}(4-v)^3& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}64-48v+12v^2-v^3 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-v^3+12v^2-48v+64\end{aligned} $$ | |
① | Find $ \left(4-v\right)^3 $ using formula $$ (A - B) = A^3 - 3A^2B + 3AB^2 - B^3 $$where $ A = 4 $ and $ B = v $. $$ \left(4-v\right)^3 = 4^3-3 \cdot 4^2 \cdot v + 3 \cdot 4 \cdot v^2-v^3 = 64-48v+12v^2-v^3 $$ |
② | Combine like terms: $$ -v^3+12v^2-48v+64 = -v^3+12v^2-48v+64 $$ |