Ordering the expressions from least to greatest: 1. 
 , 2.
, 2. 
 , 3.
, 3. 
 , 4.
, 4. 

Let's simplify each expression to compare them:
1. 
 can be simplified by multiplying the exponents:
 can be simplified by multiplying the exponents: 
 .
.
2. 
 can be simplified by subtracting the exponents in the denominator from the exponents in the numerator:
 can be simplified by subtracting the exponents in the denominator from the exponents in the numerator: 
 .
.
3. 
 can be simplified by adding the exponents:
 can be simplified by adding the exponents: 
 .
.
4. 
 can be simplified by changing the reciprocal and sign of the exponent:
 can be simplified by changing the reciprocal and sign of the exponent: 
 .
.
Now, let's order them from least to greatest:
1. 

2. 

3. 

4. 
