Answer :

To express the repeating decimal [tex]\( 3.\overline{1} \)[/tex] as a simplified fraction, follow these steps:

1. Assign a Variable: Let [tex]\( x = 3.\overline{1} \)[/tex].

2. Express the Repeating Decimal: Recognize that [tex]\( 3.\overline{1} = 3.1111...\)[/tex].

3. Move the Decimal Point: Multiply both sides of the equation by 10 to shift the decimal point one place to the right:
[tex]\[ 10x = 31.1111... \][/tex]

4. Subtract Equations: Subtract the original [tex]\( x = 3.1111... \)[/tex] from the new equation [tex]\( 10x = 31.1111... \)[/tex] to eliminate the repeating decimal:
[tex]\[ 10x - x = 31.1111... - 3.1111... \][/tex]
This simplifies to:
[tex]\[ 9x = 28 \][/tex]

5. Solve for [tex]\( x \)[/tex]: Divide both sides of the equation by 9 to isolate [tex]\( x \)[/tex]:
[tex]\[ x = \frac{28}{9} \][/tex]

Therefore, the repeating decimal [tex]\( 3.\overline{1} \)[/tex] can be written as the simplified fraction [tex]\(\frac{28}{9}\)[/tex].

So, [tex]\( 3.\overline{1} = \frac{28}{9} \)[/tex].