(6 + 9) * 7 = 105
(8 + 7) * 9 = 135
(3 + 9) * 4 = 48
(7 + 7) * 7 = 98
Вычисления:
(6 + 9) * 7 = 6 * 7 + 9 * 7 = 105
1) 6 * 7 = 42
2) 9 * 7 = 63
3) 42 + 63 = 105
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}42\\ 63\end{array}}\\ \begin{array}{r}105\end{array}\end{array}$
(8 + 7) * 9 = 8 * 9 + 7 * 9 = 135
1) 8 * 9 = 72
2) 7 * 9 = 63
3) 72 + 63 = 135
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}72\\ 63\end{array}}\\ \begin{array}{r}135\end{array}\end{array}$
(3 + 9) * 4 = 3 * 4 + 9 * 4 = 48
1) 3 * 4 = 12
2) 9 * 4 = 36
3) 12 + 36 = 48
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}12\\ 36\end{array}}\\ \begin{array}{r}48\end{array}\end{array}$
(7 + 7) * 7 = 7 * 7 + 7 * 7 = 98
1) 7 * 7 = 49
2) 7 * 7 = 49
3) 49 + 49 = 98
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}49\\ 49\end{array}}\\ \begin{array}{r}98\end{array}\end{array}$