[tex]2.x)9 \frac{11}{170}-3 \frac{25}{136}= \frac{9\cdot170+11}{170}- \frac{3\cdot136+25}{136}= \frac{4\cdot1541-5\cdot433}{680}= \frac{6164-2165}{680} \\ \\ = \frac{3999}{680} \\ \\ 170=2\cdot5\cdot17;136= 2^{3}\cdot17 \\ \\ cmmmc= 2^{3}\cdot5\cdot17=680 [/tex]
[tex]2.a) \frac{10\cdot6+5}{6}+ \frac{5\cdot3+1}{3}-\frac{2\cdot6+1}{6}= \frac{65}{6} + \frac{16}{3} -\frac{13}{6}= \frac{65+32-13}{6}= \frac{84}{6}= \frac{42}{3} [/tex]
[tex]b) \frac{7}{30} + \frac{2}{15} +\frac{1}{6}= \frac{7+2\cdot2+1\cdot5}{30}= \frac{16}{6}= \frac{8}{3} [/tex]
[tex]c) \frac{6}{7} + \frac{41}{42} +\frac{5}{12}= \frac{6\cdot12+2\cdot41+7\cdot5}{84}= \frac{191}{84}[/tex]
[tex] d)\frac{1}{7} + \frac{2}{3} +\frac{1}{2}= \frac{1\cdot6+2\cdot14+1\cdot21}{42}= \frac{56}{42} = \frac{4}{3} [/tex]
