Answer:
37
Step-by-step explanation:
 
        
             
        
        
        
(28) 2x+10+x-4=21
(29) 3x-16+4x-8=60
(30) 2x-8+3x-10=17
        
             
        
        
        
I'm assuming you meant to write 8^(-2) or  where the -2 is the exponent over the 8.
 where the -2 is the exponent over the 8.
If my assumption is correct, then we use the rule 
So,

<h3>Answer: Choice D.  1/64</h3>
 
        
             
        
        
        
75% of 60
OF MEANS times
75/100 * 60
180/4
45 
the answer is 45