(27 + 45) + 8 = 70 − неверно
96 − (13 + 57) = 26 − верно
(86 + 14) − 50 = 50 − верно
(78 − 15) + 29 = 82 − неверно
Вычисления:
(27 + 45) + 8 = 72 + 8 = 80
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}27\\ 45\end{array}}\\ \begin{array}{r}72\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}72\\ 8\end{array}}\\ \begin{array}{r}80\end{array}\end{array}$
96 − (13 + 57) = 96 − 70 = 26
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}13\\ 57\end{array}}\\ \begin{array}{r}70\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}96\\ 70\end{array}}\\ \begin{array}{r}26\end{array}\end{array}$
(86 + 14) − 50 = 100 − 50 = 50
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}84\\ 14\end{array}}\\ \begin{array}{r}100\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}100\\ 50\end{array}}\\ \begin{array}{r}50\end{array}\end{array}$
(78 − 15) + 29 = 63 + 29 = 92
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}78\\ 15\end{array}}\\ \begin{array}{r}63\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}63\\ 29\end{array}}\\ \begin{array}{r}92\end{array}\end{array}$