Brug Mix (reeks 1)

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\(41 + 48 = \ldots\)

\(\begin{align} & 41 + 48\\= & \color{green}{40} + \color{red}{1} + \color{green}{40} + \color{red}{8} \\= & \color{green}{80} + \color{red}{9} \\= & \color{red}{89} \end{align}\)