The expression 4^2/3 can be written in a radical form as:
in which if we apply the exponent to its base 4, the equation will become:
So, Option 3 is equivalent to the expression.
Let's take a look at other expressions.
Option 4 is also equivalent to the expression.
For Option 2,
To make the exponent positive, we take the reciprocal of 1/4 and that is 4. Hence,
Option 2 is also equivalent to the given expression.
Therefore, the expression that is NOT equivalent to 4^2/3 is Option 1.