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a1 = float(input("Введите a1: "))
a2 = float(input("Введите a2: "))
sign = input("Введите знак (<=, >=, =): ").strip()
b = float(input("Введите b: "))

if sign == "<=":
    print(f"{a1}*x1 + {a2}*x2 + x3 = {b}")
elif sign == ">=":
    print(f"{a1}*x1 + {a2}*x2 - x3 = {b}")
else:
    print(f"{a1}*x1 + {a2}*x2 = {b}")