We have to represent the phrase "twice the difference of a number and five" as variable expression.
A variable expression is a mathematical phrase that can contain ordinary numbers, variables (like x or y) with operations as addition, subtraction ,multiplication and division.
Let the number be 'x'.
Twice of a number =

The difference of '2x' and 5 = 2x - 5
Therefore, the variable expression representing the given phrase is "2x-5".