Question

Can we write 5xy as+5xy

Answer 1

You can write 5xy as +5xy where x and y are variables.
But x and y should be both positive numbers (greater than 0) or negative numbers (less than 0).

If x is positive number, y cannot be negative number. Or if x is negative number, y cannot be positive number.
If x and y have different signs(+ and -), 5xy cannot be written as +5xy, but as -5xy.

If no information is given about the signs of x and y, we should write it as 5xy. No sign should be given.