195. Найдите значение выражения: 2) 5 1/4(12-c) + 3 1/4(-c - 8) при с = -0,4

1. Convert mixed numbers: 21/4(12-c) + 13/4(-c - 8).
2. Distribute: (21/4 * 12 - 21/4c) + (13/4 * -c - 13/4 * 8).
3. Simplify: (63 - 21/4c) + (-13/4c - 26).
4. Combine like terms: 63 - 26 - 21/4c - 13/4c.
5. Simplify: 37 - 34/4c = 37 - 17/2c.
6. Substitute c = -0.4 = -2/5: 37 - 17/2 * (-2/5).
7. Calculate: 37 + 17/5 = 37 + 3.4 = 40.4.