a#b= a<b

c*b=c>b

c @ d =c=d

therefore a<b<c=d

The given expression is 9÷ 18×15+3−6×12.

By converting the symbols according to the given definitions we get 9−18+15÷3×6+12

Solving this BODMAS rule,we get the value as 33.

Explanation: After conversion
18 ÷ 6 x 7 – 5 + 2= 18
or, 3 x 7- 5 + 2 = 18
or, 21-5 + 2=18
or, 23-5 = 18
or, 18 = 18

Explanation:

Given expression
20-5÷ 18 x (3 + 2) = ?
After changing the signs
? = 20 + 5- 18 ÷ (3 x 2)
or, ? = 20 + 5- 18 ÷ 6
or, ? = 20 + 5- 3
or, ? = 25 -3 = 22

Explanation:

Given expression
5 N 5 P 5 L 5 M 5=?
After changing the signs
?=5 x 5 ÷ 5 + 5 – 5
or, ? = 5 + 5- 5 = 5

Explanation:
7 x 4 – 8 + 2 =>28-4 = 24

Explanation:

12 ÷ 3 + 4 – 8 = 0
or, 4 + 4 – 8 = 0
or, 8-8 = 0