Iam trying to figure out how to convert the repeating decimal of 4.54 into a fraction. can you me?

I just recently learned how to convert a repeating decimal into a fraction,
and I don't understand why I never learned this in school.

-- Take the repeating part.  Write it in the numerator of a fraction.

-- In the denominator, write the same number of ' 9s ' as the number of digits
in the numerator. 

-- There's your equivalent fraction.  Reduce (simplify) it, if it can be simplified
and if you feel like it.

In your question, the repeating part is ' 54 ' .

Make the fraction  ' 54 / 99 '.

It can be simplified (reduced) to  ' 6 / 11 '.

So  4.54 = 4 and 6/11 .

Calculate Δ = b^2 -4ac => Δ = 169 => k1 = 3/2; k2 = -5 => 2k^2 + 7k - 15 = 2*(k -3/2)(k+5) = (2k - 3)(k+5);