Question

is subtraction associative on rational numbers
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Answer 1

Answer:

A rational number is one that can be written in the form

So, the question is:

Is it always true that [Math Processing Error]?

We could formally prove that the answer is no, but we don’t need to since we can provide a simple counter-example which shows that the answer is no.

Is subtraction associative on rational numbers?

No. 5, 3, 2 are rational numbers but 5-(3–2) does not equal (5–3)-2.

The first is 5–1 = 4 but the second is 2–2=0.

Hope it will help