Решение:
Расставим знаки арифметических действий и скобки для получения верных равенств:
- \( 7 + 7 - 7 : 7 = 14 - 1 = 13 \) ... \( (7+7):7+7 = 14:7+7 = 2+7=9 \) ... \( 7 - (7+7):7 = 7 - 14:7 = 7-2=5 \) ... \( 7 - 7 + 7 - 7 = 0 \)
\( 7 - 7:7 + 7 = 7 - 1 + 7 = 13 \)
\( 7 + 7 + 7 - 7 = 14 \)
\( 7 * 7 - 7 * 7 = 49 - 49 = 0 \)
\( 7*7 - (7+7) = 49 - 14 = 35 \)
\( (7+7+7):7 = 21:7 = 3 \)
\( 7+7+7-7 = 14 \)
\( 7/7+7/7 = 1+1=2 \)
\( 77:7-7=11-7=4 \)
\( 7*7/7+7 = 7+7=14 \)
\( 7*7 - 7 - 7 = 49 - 14 = 35 \)
\( 7+7*7-7 = 7+49-7 = 49 \)
\( 7-(7-7)*7 = 7-0=7 \)
\( 7*(7-7)+7 = 7*0+7 = 7 \)
\( 7*(7/7)+7 = 7*1+7=14 \)
\( 7+7:7*7 = 7+1*7 = 7+7=14 \)
\( 7*7+7/7 = 49+1=50 \)
\( 7*7 - 7/7 = 49 - 1 = 48 \)
\( 7*7 + 7 + 7 = 49+14 = 63 \)
\( 7*(7+7/7) = 7*(7+1) = 7*8 = 56 \)
\( 7*(7+7)-7 = 7*14-7 = 98-7 = 91 \)
\( 7*(7+7+7) = 7*21 = 147 \)
\( 7*(7*7-7) = 7*(49-7) = 7*42 = 294 \)
Первое равенство:
\( 7 - 7/7 = 7-1 = 6 \)
Второе равенство:
\( 7+7+7/7 = 14+1 = 15 \)
Третье равенство:
\( 7 + 7/7 = 7+1 = 8 \)
Четвёртое равенство:
\( 7 \times (7 \times 7 - 7) = 7 \times (49 - 7) = 7 \times 42 = 294 \)
Ответ: 7 - 7/7 = 6; 7 + 7 + 7/7 = 15; 7 + 7/7 = 8; 7 * (7 * 7 - 7) = 294.