I don't understand why this is unsolvable. Help me to understand. What is wrong with this logic: x + y = 4,000 3x + 5y = 15,000 Multiply the first equation by (-3) and you get: -3x - 3y = -12,000 Now combine the equations: -3x - 3y = -12,000 3x + 5y = 15,000 2y = 3,000 y = 1,500 Women in attendance:...