19+12=31 см длина АС
Ответ: 31 см длина АС
- 6 1/5 : ( 3 2/5 - 1 1/3 ) = - 6 1/5 : ( 3 6/15 - 1 5/15) =
= - 6 1/5 : 2 1/15 = - 31/15 * 15/31 = - 1
- 3 2/3 * 1 1/2 - 1 2/3 * 1 1/2 =
= 1 1/2 * ( - 3 2/3 - 1 2/3 ) =
= 1 1/2 * ( - 5 1/3) =
= 3/2 * (- 16/3) = - 8/1 = - 8
10k-k=702
9k=702
k=702:9
k=78
Проверка
10*78-78=702