Question

Suppose you use 30 instead of 15 as a common denominator when finding 635/-313 How will that change the process for finding the sum?

1 of 2. You will get the:

A) Same result without any change
B) Correct result without the need to subtract at the end
C) Incorrect result without the need to subtract at the end
D) Incorrect result, but you will need to subtract at the end

Answer 1

Using 30 instead of 15 as a common denominator for the problem 635/-313 would result in an incorrect answer because 30 may not be the correct common multiple of the original denominators. It would not require subtracting at the end, leading to choice (C) being the correct response.

Step-by-step explanation:

If you use 30 instead of 15 as a common denominator when finding the sum of 635/-313, you will get an incorrect result, and you will not need to subtract at the end because 30 is not a correct common denominator for these numbers; therefore, the answer would be (C) Incorrect result without the need to subtract at the end.

When adding or subtracting fractions, the common denominator must be a multiple of both the original denominators. Since the denominators in the original fractions are not given in the problem, assuming 15 is used because it is a common multiple of the denominators in the actual problem, using 30 may seem like it could work as twice 15. However, this is not valid unless 30 is also a multiple of the original denominators. This can make the process incorrect because the relationship between the fractions would change. If you proceed with using an incorrect common denominator, the values of the fractions once converted are not represented accurately, which leads to an incorrect final result.