Result:
The result is rational because it can be written as the ratio of two integers and its decimal expansion does terminate or repeat.
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Step-by-step explanation:
Let's simplify the expression to get...
Therefore,
Since
, we have a rational number here. It's a fraction of two integers
We cannot have zero in the denominator.
One property of rational numbers is that the decimal expansion either terminates or it repeats (one option only).
In this case, we have a terminating decimal because 20 = 20.0; ie the decimal doesn't go on forever.
In contrast, something like 1/3 = 0.33333... has the '3's go on forever to be a repeating decimal.