Najpierw wykonujemy działania w nawiasach. Następnie w kolejności dzielenie i mnożenie. Następnie odejmowanie i dodawanie.

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a)

$787\stackrel{2}{-}\stackrel{1}{\overbrace{4\cdot 92}}=787-368=419$  

$\begin{array}{r}\stackrel{3}{}92\\ \underline{\cdot 4}\\ 368\end{array}$

$\begin{array}{r}7\stackrel{7}{\cancel{8}}\stackrel{17}{\cancel{7}}\\ \underline{-368}\\ 419\end{array}$

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b)

$2\stackrel{2}{\cdot }\stackrel{1}{\overbrace{\left(894+1566\right)}}=2\cdot 2460=4920$  

$\begin{array}{r}\stackrel{1}{1}\stackrel{1}{5}\stackrel{1}{6}6\\ \underline{+894}\\ 2460\end{array}$

$\begin{array}{r}2\stackrel{1}{4}60\\ \underline{\cdot 2}\\ 4920\end{array}$

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c)

$431\stackrel{2}{+}\stackrel{1}{\overbrace{1240:2}}=431+620=1051$  

$\begin{array}{l}\underline{620}\\ 1240:2\\ \underline{-12}\\ 04\\ \underline{-4}\\ 00\\ \underline{-0}\\ 0\end{array}$

$\begin{array}{r}\stackrel{1}{}431\\ \underline{+620}\\ 1051\end{array}$

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d)

$\stackrel{1}{\overbrace{\left(3260-1648\right)}}\stackrel{2}{\text{:}}2=1612:2=806$  

$\begin{array}{r}\stackrel{2}{\cancel{3}}\stackrel{12}{\cancel{2}}\stackrel{5}{\cancel{6}}\stackrel{10}{\cancel{0}}\\ \underline{-1648}\\ 1612\end{array}$

$\begin{array}{l}\underline{806}\\ 1612:2\\ \underline{-16}\\ 01\\ \underline{-0}\\ 12\\ \underline{-12}\\ 0\end{array}$