If 'x' means addition, '' means division, '÷' means subtraction and '+' means multiplication, then which of the equations is correct?

• 16 x 5 ÷ 10 + 4 - 3 = 19
• 16 + 5 ÷ 10 x 4 - 3 = 9
• 16 + 5 - 10 x 4 ÷ 3 = 9
• 16 - 5 x 10 ÷ 4 + 3 = 12