So some quick tips for inequalities:
**What you do to one side you HAVE TO do it to the other 2**
**If you ever divide a negative number past the inequality signs, the signs FLIP!!** 
(e.g. 2>-5x>25)
-2/5 <x < -5
I hope that this has helped!
        
             
        
        
        
Answer:
option (a) $6,240
Step-by-step explanation:
Given:
Purchasing cost of the equipment = $82,000
Estimated life = 5 years
Salvage value = $4,000
Revised expected life = 8 years
Now, 
Depreciation per year =  
therefore, 
The accumulated Depreciation at the beginning of year 4 
= Annual depreciation × years passed
= 15,600 × 3 
= $46,800
Thus,
The book value at the beginning of year 4 
= Purchasing cost - Depreciation 
= $82,000 - $46,800 
= $35,200
Now,
The remaining life = Revised estimated life - Years passed 
= 8 - 3 
= 5 years
therefore,
Depreciation expense = 
=  
= $6,240
Hence, 
The correct answer is option (a) $6,240
 
        
             
        
        
        
Answer:
625b^6
Step-by-step explanation:
= 5^3 * 5b^6
= 5^3 * 5 
= 625