| $$ \begin{aligned}x+0.04x+0.1x& \xlongequal{ }x+0x+0x \xlongequal{ } \\[1 em] & \xlongequal{ }x \cancel{0x} \cancel{0x} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{x} \, \color{red}{ \cancel{0x}} \, \, \color{red}{ \cancel{0x}} \, = \color{red}{x} $$ |