Tap the blue circles to see an explanation.
| $$ \begin{aligned}2 \cdot \frac{\frac{x}{x}}{20}+\frac{x}{30}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}2 \cdot \frac{x}{20x}+\frac{x}{30} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{2x}{20x}+\frac{x}{30} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{20x^2+60x}{600x}\end{aligned} $$ | |
| ① | Divide $ \dfrac{x}{x} $ by $ 20 $ to get $ \dfrac{ x }{ 20x } $. Step 1: To divide rational expressions, multiply the first fraction by the reciprocal of the second fraction. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} \frac{ \frac{x}{x} }{20} & \xlongequal{\text{Step 1}} \frac{x}{x} \cdot \frac{\color{blue}{1}}{\color{blue}{20}} \xlongequal{\text{Step 2}} \frac{ x \cdot 1 }{ x \cdot 20 } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ x }{ 20x } \end{aligned} $$ |
| ② | Multiply $2$ by $ \dfrac{x}{20x} $ to get $ \dfrac{ 2x }{ 20x } $. Step 1: Write $ 2 $ as a fraction by putting $ \color{red}{1} $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} 2 \cdot \frac{x}{20x} & \xlongequal{\text{Step 1}} \frac{2}{\color{red}{1}} \cdot \frac{x}{20x} \xlongequal{\text{Step 2}} \frac{ 2 \cdot x }{ 1 \cdot 20x } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 2x }{ 20x } \end{aligned} $$ |
| ③ | Add $ \dfrac{2x}{20x} $ and $ \dfrac{x}{30} $ to get $ \dfrac{ \color{purple}{ 20x^2+60x } }{ 600x }$. To add raitonal expressions, both fractions must have the same denominator. |