4 (e)  
sin^8 x - cos^8 x
= (sin^4 x + cos^4 x)(sin^4 x - cos^4 x)
= (sin^4 x + cos^4 x)(sin^2 x - cos^2x)(sin^2 x +cos^2 x)
=  (sin^4x + cos^4 x)( sin^2 x- cos^2 x)
Sorry I cant do 4 (d).
        
             
        
        
        
Answer:
   4 chocolates
Step-by-step explanation:
Before Luke started eating, there were 8. This is 2/3 of what Sara had to start with, so she started with 12. That is 3/4 of what Mike started with, so he started with 16.
Jill left 4/5 of what she started with, so she must have started with 20. Jake ate 1/6 and left 5/6, so 20 is 5 times the number Jake ate.
Jake ate 4 chocolates.
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Jill ate 4; Mike ate 4; Sara ate 4; and Luke ate 4.
 
        
             
        
        
        
7(x-1)+3 where x is how many numbers are being added together