Convert 0.09¯¯¯¯¯

to a rational number in simplest form.

Show your work.

1 answer

Let \( x = 0.09\overline{09} \) (the bar indicates that the "09" repeats indefinitely). We can express \( x \) mathematically as follows:

\[ x = 0.09090909\ldots \]

To eliminate the repeating decimal, we can multiply \( x \) by \( 100 \) (since the repeating part is 2 digits long):

\[ 100x = 9.09090909\ldots \]

Now, we have two equations:

  1. \( x = 0.09090909\ldots \) (1)
  2. \( 100x = 9.09090909\ldots \) (2)

Next, we will subtract equation (1) from equation (2):

\[ 100x - x = 9.09090909\ldots - 0.09090909\ldots \]

This simplifies to:

\[ 99x = 9 \]

Now, we can solve for \( x \):

\[ x = \frac{9}{99} \]

Now we simplify \(\frac{9}{99}\):

The greatest common divisor (GCD) of 9 and 99 is 9. Thus, we divide the numerator and denominator by 9:

\[ x = \frac{9 \div 9}{99 \div 9} = \frac{1}{11} \]

Therefore, the rational number in simplest form that corresponds to \( 0.09\overline{09} \) is:

\[ \boxed{\frac{1}{11}} \]