4. In a certain code language, '-' represents '+', '+' represents 'x', 'x' represents '÷' and '÷' represents '-'. Find out the answer to the following question. 2 - 12 + 10 x 5 ÷ 12 = ?
5. In a certain code language, ?book is tough? is written as ?fu la mi?, ?tough can easy? is written as ?fu muk po? and ?easy not book? is written as ?ti po la?.What is the code for ?tough? in that code language?