Brug Mix (reeks 1)

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\(57 + 10 = \ldots\)

\(\begin{align} & 57 + 10\\= &10+57\\= &10 + \color{green}{50} + \color{red}{7} \\= & \color{green}{60} + \color{red}{7} \\= & \color{red}{67} \end{align}\)