Lesson Page

 

 


  Math B

Evaluating Expressions with Fractional  Powers

 

When asked to "evaluate" an expression, you are most likely being asked to find a numerical value.  You should not stop until you arrive at the best, and simplest, form for the answer.   Before we go any further, refresh your memory on the rules which apply to working with exponents:
 

R e m e m b e r !
 ... exponent rules work with BOTH integers and fractions!!

Rule Example

 

Look carefully at the following problem.  Can you see the exponent rules at work?  Pay particular attention to what is considered the "best" final answer.  When evaluating expressions, don't lose valuable points on an exam question (that you most likely could answer easily) because you did not express the answer in its "best" form.

Evaluate this expression:

 

 

  

Is this the answer?

No.  To evaluate means to arrive at the simplest numerical answer possible.

The answer must now be simplified further.  

Now that's 
an answer!!

 

Check out how these problems are evaluated using the rules of exponents:

Problem: Answer:

Evaluate:    

Evaluate:   

If a = 8, find the value of:   

 


           F. Roberts