18. 8 less than a number x. Which of the following expressions represents the preceding phrase?
Answer: A
x - 8
The expression that represents "8 less than a number x" is x - 8, which indicates that 8 is subtracted from the variable x.
A) x - 8
Option A is correct because it directly translates the phrase "8 less than a number x" into mathematical terms, accurately reflecting the operation of subtraction from x.
B) 8 - x
Option B is incorrect because it reverses the order of subtraction, suggesting that x is subtracted from 8, which does not align with the original phrase indicating a decrease from x.
C) x + 8
Option C is incorrect as it implies that 8 is being added to x, which contradicts the requirement of expressing "8 less than" the number.
D) 8x
Option D is incorrect since it represents the multiplication of 8 and x, which does not relate to the operation of subtraction described in the phrase.
Conclusion
The correct answer is x - 8 because it accurately conveys the concept of subtracting 8 from the number x. All other options either misinterpret the phrase or apply incorrect mathematical operations. Thus, x - 8 is the only expression that correctly represents the stated condition.