$$ \begin{aligned}(a+b)^3& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}a^3+3a^2b+3ab^2+b^3\end{aligned} $$ | |
① | Find $ \left(a+b\right)^3 $ using formula $$ (A + B) = A^3 + 3A^2B + 3AB^2 + B^3 $$where $ A = a $ and $ B = b $. $$ \left(a+b\right)^3 = a^3+3 \cdot a^2 \cdot b + 3 \cdot a \cdot b^2+b^3 = a^3+3a^2b+3ab^2+b^3 $$ |