08. Вычислите: а) 18 · (1/9)² − 20 · 1/9; б) (19/8 + 11/12) : 5/48; в) (2 3/4 + 2 1/5) · 16

а) \(18\cdot\left(\frac19\right)^2-20\cdot\frac19=18\cdot\frac1{81}-\frac{20}{9}=\frac29-\frac{20}{9}=-2\).

б) \(\left(\frac{19}{8}+\frac{11}{12}\right):\frac5{48}=\left(\frac{57}{24}+\frac{22}{24}\right)\cdot\frac{48}{5}=\frac{79}{24}\cdot\frac{48}{5}=\frac{158}{5}=31\frac35\).

в) \(\left(2\frac34+2\frac15\right)\cdot16=\left(\frac{11}{4}+\frac{11}{5}\right)\cdot16=\frac{99}{20}\cdot16=\frac{396}{5}=79\frac15\).