5lb book of problems. Pg 460 - Ch 11 - Q 38.

[Nadirshah]

This one totally went over my head. I cant grasp the explanation in the book. Any ideas

[tommywallach]

Hey Nadir,

Unfortunately there's no other way to do it. Just testing numbers randomly wouldn't help.

Basically, they're saying that a certain number x is one less than the reciprocal of whatever part of x comes after the decimal.

As an example.

1.2

The part after the decimal = .2

The reciprocal = 1/.2 = 5

Is 5 equal to 1.2 + 1? Nope. So that isn't our x.

Finding the x at random is impossible, but we can use the classic technique of plugging in the value from the other column. This works, and is clearly our x value.

You can ignore the rest of the explanation, which is just trying to prove it more fundamentally/algebraically. Who cares? We've proven it with the number itself, and that's enough.

-t

[Nadirshah]

Thanks T

[tommywallach]

Glad to help! Tough question! : )

-t