(8-6 1/4)÷(-5/8)-9×(-1/2-2/5) решите этот пример 20 б

8-6 1/4=8-25/4=32/4-25/4=7/4
-1/2-2/5=-5/10-4/10=-9/10
7/4÷(-5/8)=-14/5
-9×(-9/10)=81/10
-14/5-81/10=-28/10+81/10=53/10=5,3

( 8 - 6 1/4) : (-5/8) - 9 * (-1/2 - 2/5) = 5,3

1) 8 - 6  1/4 = 8 4/4 - 6 1/4 = 1 3/4
2) - 1/2 - 2/5 = - 5/10  - 4/10 = - 9/10
3) 1 3/4 : (-5/8) = - (7/4 : 5/8) = - (7/4 * 8/5) = - 14/5 = - 2 4/5
4) 9 * (- 9/10) = - (9 * 9/10) = - 8 1/10
- 2 4/5 - (-8 1/10) = - 2 4/5 + 8 1/10 = - 14/5 + 81/10 = -28/10 + 81/10 = 53/10 = 5 3/10 = 5,3