Coding and Decoding Questions

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

If ENTRY is coded as 98462 and STEADY is coded as 749312, then how is NEATNESS written in that code?

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?

If "+" means "minus", "x" means "divided by", "÷" means "plus" and "-" means "multiplied by", then
76 x 4 + 4 – 12 ÷ 37 = ?

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

In a certain code language, "OCEAN" is written as "PEHES". How is "RIVER" written in that code language?