\(\frac{99}{98}-\frac{98}{97}-\frac{1}{97x98}\)
\(=\frac{99}{98}-\frac{98}{97}-\left(\frac{1}{97}-\frac{1}{98}\right)\)
\(=\frac{99}{98}-\frac{98}{97}-\frac{1}{97}+\frac{1}{98}=\left(\frac{99}{98}+\frac{1}{98}\right)+\left(-\frac{98}{97}-\frac{1}{97}\right)\)
\(=\frac{100}{98}-\frac{99}{97}=-\frac{1}{4753}\)