[tex][ \frac{2}{3} * \frac{3}{10} - \frac{1}{10} ] - \frac{1}{1} = [ \frac{6}{30}^{6} - \frac{1}{10}]- \frac{1}{1}= [ \frac{1}{5}- \frac{1}{10} ]- \frac{1}{1}= \frac{2-1}{10} - \frac{1}{1} = \frac{3}{10} - \frac{1}{1} [/tex]
=[tex]= - \frac{7}{10} [/tex]