Tap the blue circles to see an explanation.
| $$ \begin{aligned}\frac{x}{1}+\frac{x^2}{3}+\frac{x^2}{5}+\frac{x^2}{7}+\frac{x^2}{9}+\frac{x^2}{11}+\frac{x^2}{13}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x^2+3x}{3}+\frac{x^2}{5}+\frac{x^2}{7}+\frac{x^2}{9}+\frac{x^2}{11}+\frac{x^2}{13} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{8x^2+15x}{15}+\frac{x^2}{7}+\frac{x^2}{9}+\frac{x^2}{11}+\frac{x^2}{13} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{71x^2+105x}{105}+\frac{x^2}{9}+\frac{x^2}{11}+\frac{x^2}{13} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{248x^2+315x}{315}+\frac{x^2}{11}+\frac{x^2}{13} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}\frac{3043x^2+3465x}{3465}+\frac{x^2}{13} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle6}{\textcircled {6}} } }}}\frac{43024x^2+45045x}{45045}\end{aligned} $$ | |
| ① | Add $ \dfrac{x}{1} $ and $ \dfrac{x^2}{3} $ to get $ \dfrac{ \color{purple}{ x^2+3x } }{ 3 }$. To add raitonal expressions, both fractions must have the same denominator. |
| ② | Add $ \dfrac{x^2+3x}{3} $ and $ \dfrac{x^2}{5} $ to get $ \dfrac{ \color{purple}{ 8x^2+15x } }{ 15 }$. To add raitonal expressions, both fractions must have the same denominator. |
| ③ | Add $ \dfrac{8x^2+15x}{15} $ and $ \dfrac{x^2}{7} $ to get $ \dfrac{ \color{purple}{ 71x^2+105x } }{ 105 }$. To add raitonal expressions, both fractions must have the same denominator. |
| ④ | Add $ \dfrac{71x^2+105x}{105} $ and $ \dfrac{x^2}{9} $ to get $ \dfrac{ \color{purple}{ 248x^2+315x } }{ 315 }$. To add raitonal expressions, both fractions must have the same denominator. |
| ⑤ | Add $ \dfrac{248x^2+315x}{315} $ and $ \dfrac{x^2}{11} $ to get $ \dfrac{ \color{purple}{ 3043x^2+3465x } }{ 3465 }$. To add raitonal expressions, both fractions must have the same denominator. |
| ⑥ | Add $ \dfrac{3043x^2+3465x}{3465} $ and $ \dfrac{x^2}{13} $ to get $ \dfrac{ \color{purple}{ 43024x^2+45045x } }{ 45045 }$. To add raitonal expressions, both fractions must have the same denominator. |