Question

5X4/2-4EXPONET OF 2

Answer 1

There are many ways to interpret what you have written. You must use parentheses to make clear in what order the operations are perfomed. For example

5*4/(2 -4^-2)= 20/(2-1/16) = 10.323, or
(5*4/2)- (4^2)= 10 - 16 = -6
There are other possibilities as well.