Coding and Decoding Questions

If 1∆-5=5, 4∆7=-28 and -1∆-3=-3, then find the value of 8∆-8 =?

In a certain code language, "READ" is written as "18514". How is "RATE" written in that code language?

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?

27 x 3 ÷ 30 + 5 - 125 = ?

In a certain code language, "COPIOUS" is written as "2345389" and "GENEROUS" is written as "16760389". How is "PIGEON" written in that code language?

The following equation is incorrect. Which two signs should be interchanged to correct the equation? 12 - 6 x 5 + 20 ÷ 4 = 31

If ETHANOL is coded as HWKDQRO, then how will MIX be coded as?

If "-" means "plus", "x" means "divide", "÷" means "multiply" and "+" means "minus", then 26 + 400 x 20 – 21 ÷ 12 = ?

If IMPLORE is coded as GKNJMPC, then how will HUB be coded as?