\(1\frac{6}{12}-1\frac9{12}\)
To make it easier, convert them to improper fractions.
\(=\frac{18}{12}-\frac{21}{12}\)
There is already a common denominator, so just subtract the fractions.
\(=\frac{18-21}{12} \\~\\ =\frac{-3}{12}\)
Reduce.
\(=-\frac{1}{4}\)
