Which expression best represents the difference between triple a number and double a number?
a. 3x - 2x
b. 2x - 3x
c. x3 - x2
d. x2 - x3

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.