3. In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 56 ÷ 8 + 12 - 72 = ?
10. In a certain code language, 'x' represents '+', '÷' represents 'x', '' represents '÷' and '+' represents ''. Find out the answer to the following question. 5 ÷ 4 10 + 7 x 16 = ?