$a^{-n}={\Large\frac{1}{a^n}}$, $a≠0$

$2^{-2}+4^{-1}={\Large\frac{1}{2^2}}+{\Large\frac{1}{4}}={\Large\frac{1}{4}}+{\Large\frac{1}{4}}={\Large\frac{1}{2}}=0,5$

$7,17-5{\Large\frac{3}{4}}=7,17-5,75=1,42$

$16,92+{\Large\frac{3}{50}}=16,92+0,06=16,98$

$\left(6{\Large\frac{1}{5}}+2{\Large\frac{1}{8}}\right):111=\left(8+{\Large\frac{8+5}{40}}\right):111=8{\Large\frac{13}{40}}:111={\Large\frac{333}{40\cdot111}}={\Large\frac{3}{40}}=0,075$

${\Large\frac{0,8}{18}}∶{\Large\frac{4}{3,6}}={\Large\frac{0,8\cdot3,6}{18\cdot4}}={\Large\frac{8\cdot36}{18\cdot4\cdot100}}={\Large\frac{2\cdot2}{1\cdot1\cdot100}}={\Large\frac{4}{100}}=0,04$

${\Large\frac{-7\cdot(-16)}{200\cdot(-0,5)}}=-{\Large\frac{7\cdot16\cdot2}{200\cdot0,5\cdot2}}=-{\Large\frac{112}{100\cdot1}}=-1,12$

${\Large\frac{9,2 - 1,6}{0,04 - 0,24}}={\Large\frac{7,6}{-0,2}}=-{\Large\frac{76}{2}}=-38$

$\left({\Large\frac{17}{18}}-{\Large\frac{7}{12}}\right):{\Large\frac{13}{45}}=\left({\Large\frac{17\cdot2-7\cdot3}{36}}\right)\cdot{\Large\frac{45}{13}}={\Large\frac{34-21}{36}}\cdot{\Large\frac{45}{13}}={\Large\frac{13\cdot45}{36\cdot13}}={\Large\frac{1\cdot5}{4\cdot1}}=1,25$

${\Large\frac{0,08\cdot10^{-7}}{10^{-9}}}=0,08\cdot10^{-7-(-9)}=0,08\cdot10^2=0,08\cdot100=8$

${\Large\frac{0,08\cdot10^{-7}}{10^{-9}}}={\Large\frac{0,08\cdot10^{9}}{10^{7}}}=0,08\cdot10^2=8$