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Using algebra, show that 1.381 (the 81 is recurring) subtract 0.81 ( the 81 is recurring) equals to 31/55

User Ajay Soman
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1 Answer

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it is true that 81 as recurring decimal equals to 3/55

How to show that 81 as recurring decimal equals to 3/55

From the question, we have the following parameters that can be used in our computation:

1.381818181.....

This can be expressed as

1.3 + 0.081 + 0.00081 + 0.0000081

From the above, we have

First term, a = 0.081

Common ratio, r = 0.01

The sum to infinity on a geometric sequence is

S = a/(1 - r)

So, we have

S = 0.081/(1 - 0.01)

S = 0.081/(0.99)

Evaluate

S = 81/990

Simplify

S = 9/110

This gives

S = 3/55

Hence, 81 as recurring decimal equals to 3/55

Question

Using algebra, show that the 81 in 1.381818181..... equals to 3/55

User IronMan
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