1. In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 45 x 5 + 2 - 20 = ?
3. In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 9 + 3 - 72 x 6 ÷ 3 = ?
7. In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 42 x 7 ÷ 7 + 9 - 62 = ?
10. In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question? 12 x 6 ÷ 5 + 4 = ?