2 1/13 * (5 - 11 2/13) + 11 2/13 * (2 1/13 - 5)=
2 1/13 * 5 - 2 1/13 * 11 2/13 + 11 2/13 * 2 1/13 - 11 2/13 * 5=
2 1/13 * 5 - 11 2/13 * 5=
(2 1/13 - 11 2/13)*5= - 9 1/13*5= - 45 5/13
думаю так...
Ответ:
1) 12 = 10+2
2) 12+7 = (10+2)+7 = 10+(2+7) = 10+9 = 19
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6+5 = (5+1)+5 = (5+5)+1 = 10+1 = 11
3) 13+6 = (10+3)+6 = 10+(3+6) = 10+9 = 19
15+3 = (10+5)+3 = 10+(5+3) = 10+8 = 18
Решениеееееееееееееееееееееее