\(B=-\dfrac{1}{99}-\dfrac{1}{99.98}-\dfrac{1}{98.98}-...-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
\(B=-\left(\dfrac{1}{99}+\dfrac{1}{99.98}+\dfrac{1}{98.97}+...+\dfrac{1}{3.2}+\dfrac{1}{2.1}\right)\)
\(B=-\left(\dfrac{1}{99}+\dfrac{1}{98}-\dfrac{1}{99}+\dfrac{1}{97}-\dfrac{1}{98}+...+\dfrac{1}{2}-\dfrac{1}{3}+1-\dfrac{1}{2}\right)\)
\(B=-1\)