Daniil
см в обьяснении
1)
((5*x**2-3*y)/(x**2*y)+(6x-2y**2)/(x**2*y**2))
2)
a = int(input())
b = int(input())
c = (a+b)/2
print(c)
3)
a = float(input())
b = float(input())
c = float(input())
if a > 1. 3 and a < 4. 6:
print(a)
if b > 1. 3 and b < 4. 6:
print(b)
if c > 1. 3 and c < 4. 6:
print(c)
stem