High School

Which of the following statements are true?

I. The difference between -1.4 and -8.3 is positive.
II. -1.4 + 8.3 has the same value as the difference between -1.4 and -8.3.
III. The difference between -8.3 and -1.4 has the same value as the difference between -1.4 and -8.3.
IV. None of the statements are true.

Answer :

Final answer:

Ootion (I), The difference between -1.4 and -8.3 is positive, and -1.4 + 8.3 has the same value as that difference. However, the differences calculated in reverse order (-8.3 - -1.4 vs. -1.4 - -8.3) are not the same because subtraction is not commutative.

Explanation:

To address the student's question, we need to examine each of the statements given:

  1. The difference between -1.4 and -8.3 is positive because when we subtract a negative number, it's equivalent to adding its positive counterpart. Calculating the difference: -1.4 - (-8.3) changes to -1.4 + 8.3, which equals 6.9, which is indeed positive.
  2. -1.4 + 8.3 does have the same value as the difference between -1.4 and -8.3. This is an application of the rule where subtracting a negative number is the same as adding its positive equivalent, resulting in the same value, 6.9.
  3. The difference between -8.3 and -1.4 does not have the same value as the difference between -1.4 and -8.3 because subtraction is not a commutative operation like addition. If we calculate -8.3 - (-1.4), we get -6.9, which has the opposite sign as compared to the difference calculated in the other order.

Based on our analysis, the correct statement is I.