MathJax 展示步骤

hbghlyj

\toggle 宏（产生 MathML <maction> 元素）$$
\require{action}
\def\longest{x(x+1) + 1(x+1)}
\def\click{\rlap{\enclose{roundedbox}{\small\text{下一步}}}\hphantom{\longest}}
\def\={\phantom{ {}={} }}
(x+1)^2
\toggle
  {\begin{aligned}[t]& = \click\end{aligned}}
  {\begin{aligned}[t]& = (x+1)(x+1)\\[3px]&\=\click\end{aligned}}
  {\begin{aligned}[t]& = (x+1)(x+1)\\[3px]& = x(x+1) + 1(x+1)\\&\=\click\end{aligned}}
  {\begin{aligned}[t]& = (x+1)(x+1)\\[3px]& = x(x+1) + 1(x+1)\\[3px]& = (x^2+x) + (x+1)\\[3px]&\=\click\end{aligned}}
  {\begin{aligned}[t]& = (x+1)(x+1)\\[3px]& = x(x+1) + 1(x+1)\\[3px]& = (x^2+x) + (x+1)\\[3px]& = x^2 + (x + x) + 1\\[3px]&\=\click\end{aligned}}
  {\begin{aligned}[t]& = (x+1)(x+1)\\[3px]& = x(x+1) + 1(x+1)\\[3px]& = (x^2+x) + (x+1)\\[3px]& = x^2 + (x + x) + 1\\[3px]& = x^2 + 2x + 1\end{aligned}}
\endtoggle
$$

kuing

还能这样玩，腻害😃😃😃