Correct Answer:
C. x
The correct answer is x because the arithmetic mean of two terms is calculated by finding their average.
- Step 1 (Set up the formula): The arithmetic mean formula for two values a and b is
(a + b) / 2. Substituting our values gives((x - 3) + (x + 3)) / 2. - Step 2 (Simplify the numerator): Combining like terms in the numerator, the -3 and +3 cancel each other out, leaving
x + x = 2x. - Step 3 (Divide by 2): Dividing
2x / 2cancels out the 2s, which leaves us with x. - Incorrect Options:
- -6 is incorrect because it represents the difference between the bounds, not the central average.
- 6 is incorrect because it is the total distance between the two expressions, not their midpoint.
- None of these is incorrect because option 3 perfectly satisfies the arithmetic mean definition.