a) [tex]\[ 0 . \dot{5}=\frac{5}{9} \][/tex]
Use the fact above to convert 0.05 to a fraction.

b) Using part (a) or otherwise, convert [tex]\[ 0.2 \dot{5} \][/tex] to a fraction in its simplest form.



Answer :

Let's tackle each part of the question step-by-step:

### Part (a)
Convert [tex]\(0.05\)[/tex] to a fraction.

1. Realize that [tex]\(0.05\)[/tex] is a finite decimal.
2. Since [tex]\(0.05\)[/tex] has two decimal places, it can be written as [tex]\(\frac{5}{100}\)[/tex].
3. Simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor (GCD), which is 5:
[tex]\[ \frac{5 \div 5}{100 \div 5} = \frac{1}{20} \][/tex]
Therefore, [tex]\(0.05\)[/tex] as a fraction is [tex]\(\frac{1}{20}\)[/tex].

### Part (b)
Convert [tex]\(0.2\dot{5}\)[/tex] (which is [tex]\(0.25555\ldots\)[/tex]) to a fraction.

1. Let's set up the repeating decimal. Let [tex]\(x = 0.25555\ldots\)[/tex].
2. Realize that the repeating part starts after the "2":
[tex]\[ x = 0.25555\ldots \][/tex]
3. To eliminate the repeating part, multiply [tex]\(x\)[/tex] by 10 so that the repeating part lines up:
[tex]\[ 10x = 2.5555\ldots \][/tex]
4. Now, we have two equations:
[tex]\[ \begin{cases} x = 0.25555\ldots & \text{(i)} \\ 10x = 2.5555\ldots & \text{(ii)} \end{cases} \][/tex]
5. Subtract equation (i) from equation (ii):
[tex]\[ 10x - x = 2.5555\ldots - 0.25555\ldots \][/tex]
[tex]\[ 9x = 2.3 \][/tex]
6. Solve for [tex]\(x\)[/tex] by dividing both sides by 9:
[tex]\[ x = \frac{2.3}{9} \][/tex]
7. As a fraction, [tex]\(2.3\)[/tex] needs to be converted into an improper fraction first. Recall that [tex]\(2.3 = 2 + \frac{3}{10} = \frac{23}{10}\)[/tex]:
[tex]\[ x = \frac{\frac{23}{10}}{9} = \frac{23}{10} \times \frac{1}{9} = \frac{23}{90} \][/tex]

Thus, the fraction for [tex]\(0.2\dot{5} \)[/tex] in its simplest form is [tex]\(\frac{23}{90}\)[/tex].