☝️=✌️

$\begin{aligned} 23^2=&23 \cdot 23 \quad & \ldots ① \\ 23^2-23^2=&23 \cdot 23-23 \cdot 23 \quad & \ldots ② \\ (23+23)(23-23)=& 23(23-23) \quad & \ldots ③ \\ (23+23)\cdot \cancel{0}=&23\cdot \cancel{0} \quad & \ldots ④ \\ 23=&46 ⇒ 1=2 \quad & \ldots ⑤\end{aligned}$

The above equations lead us to a conclusion that $1 = 2$. Then which of these steps contains the flaw.

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