C. x³ - x²
In word problems, there terms which indicate the mathematical operation that needs to be performed. 
difference = refers to the answer in subtraction
triple a number or double a number refers to the number of times a number is multiplied by itself.
in triple a number = a number is multiplied by itself three times.
in double a number = a number is multiplied by itself two times.
It would initially look like this: (x * x * x) - (x * x); to simplify the expression, a number to be multiplied is written down and the number of times it will multiply by itself is noted on the upper right side of the number when we look at it.
Thus: x³ - x² is the correct expression that best describes the word problem above.
        
                    
             
        
        
        
Grayson did not simplify the question
        
             
        
        
        
The annual returns will be calculated as follows:
a] Here we use the formula:
A=p(1+r/100)^n
A=future amount
p=principle
r=returns
n=time
We are given:
A=500, p=400, t=1
Plugging the values in the formula we obtain:
500=400(1+r)^1
simplifying and solving for r:
1.25=1+r
thus
r=1.25-1
r=0.25~25%
b] Using the formula above:
A=p(1+r/100)^n
A=2500+100=2600, p=2000, n=1 year
plugging the values in the equation we obtain:
2600=2000(1+r)^1
simplifying and solving for r we obtain:
2600/2000=1+r
1.3=1+r
hence
r=1.3-1
r=0.3~30%
        
             
        
        
        
Answer:
maybe it means how many shirts