$$-12a^2b\dfrac{u}{3}ab^5=\dfrac{12a^3b^6u}{3}$$
Tap the blue circles to see an explanation.
| $$ \begin{aligned}-12a^2b\frac{u}{3}ab^5& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{12a^2bu}{3}ab^5 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{12a^3bu}{3}b^5 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{12a^3b^6u}{3}\end{aligned} $$ | |
| ① | Multiply $12a^2b$ by $ \dfrac{u}{3} $ to get $ \dfrac{ 12a^2bu }{ 3 } $. Step 1: Write $ 12a^2b $ as a fraction by putting $ \color{red}{1} $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} 12a^2b \cdot \frac{u}{3} & \xlongequal{\text{Step 1}} \frac{12a^2b}{\color{red}{1}} \cdot \frac{u}{3} \xlongequal{\text{Step 2}} \frac{ 12a^2b \cdot u }{ 1 \cdot 3 } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 12a^2bu }{ 3 } \end{aligned} $$ |
| ② | Multiply $ \dfrac{12a^2bu}{3} $ by $ a $ to get $ \dfrac{ 12a^3bu }{ 3 } $. Step 1: Write $ a $ as a fraction by putting $ \color{red}{ 1 } $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} \frac{12a^2bu}{3} \cdot a & \xlongequal{\text{Step 1}} \frac{12a^2bu}{3} \cdot \frac{a}{\color{red}{1}} \xlongequal{\text{Step 2}} \frac{ 12a^2bu \cdot a }{ 3 \cdot 1 } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 12a^3bu }{ 3 } \end{aligned} $$ |
| ③ | Multiply $ \dfrac{12a^3bu}{3} $ by $ b^5 $ to get $ \dfrac{ 12a^3b^6u }{ 3 } $. Step 1: Write $ b^5 $ as a fraction by putting $ \color{red}{ 1 } $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} \frac{12a^3bu}{3} \cdot b^5 & \xlongequal{\text{Step 1}} \frac{12a^3bu}{3} \cdot \frac{b^5}{\color{red}{1}} \xlongequal{\text{Step 2}} \frac{ 12a^3bu \cdot b^5 }{ 3 \cdot 1 } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 12a^3b^6u }{ 3 } \end{aligned} $$ |