№7
6 : (- 1 1/10) = а : ( - 7 1/3)
6 * ( - 7 1/3) = а * (- 1 1/10)
а = 6 * ( - 7 1/3) : ( - 1 1/10)
а = - 44 : ( - 1 1/10)
а = 44 : 11/10
а = 40
№8
-3,8 : (2 3/7 + 3/7 * (- 2,5)) - 2 19/25 = - 5 14/25
1) 3/7 * ( - 2,5) = - 3/7 * 5/2 = - 15/14 = - 1 1/14
2) 2 3/7 + (- 1 1/14) = 1 5/14
3) - 3,8 : 1 5/14 = - 19/5 : 19/14 = - 2 4/5
4) -2 4/5 - 2 19/25 = - 4 39/25 = - 5 14/25