1.2x10^-2 cannot be written as an integer.
Allow me to write the other three choices as integers.
Square 49 or square root of 49( I am not sure which you meant but both can be written as an integer)
Square root of 49 = 7
49 squared = 2401
-3^0 = 1
18/3 = 6
All these solutions are integers except the remaining solution.
