A)  
   
   
       
    
   
  
You almost made it to here, but you missed a sign
by skipping a step, causing you to get a 5 where there 
should be a 7. 

Now enclose both sides in parentheses:

   

Now multiply both sides by LCD =  or 

   

Cancel:

   
 
        









---------------------

Although the above method is correct, it is
not the normal way to do it.  You begin by
multiplying through by the LCD, not waiting
until later, as you did above. Here is how
it is normally done:

Do the first two steps as you did above:

       
    

Now enclose every term in parentheses:

   

Multiply every term on both sides by the 
LCD =  or 

   

Cancel:

   

   
   
   
   
   
   
   

   
B)

Enclose both sides in parentheses:

   

Raise both sides to the reciprocal of  power,
which is the  power:

   

Multiply exponents on the left,  = 

Write the right side using the rule 

   

Since the cube root of 125 is 5, we have:

   

   

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c)  

Enclose both sides in parentheses:

   

Cube both sides:

   

   

   

When you cube a cube root you take away
the radical:

   

   

   

   

   

Edwin