Вычислите: \((8{,}25 \cdot \frac{10}{11}-10)\cdot(11\frac{2}{3}:2\frac{2}{9}-6{,}15)+12{,}7:(-2\frac{1}{2})\).

\[8.25\cdot\frac{10}{11}=\frac{33}{4}\cdot\frac{10}{11}=\frac{15}{2}=7.5,\]

\[8.25\cdot\frac{10}{11}-10=7.5-10=-2.5=-\frac52.\]

\[11\frac23:2\frac29=\frac{35}{3}:\frac{20}{9}=\frac{35}{3}\cdot\frac{9}{20}=\frac{21}{4}=5.25,\]

\[11\frac23:2\frac29-6.15=5.25-6.15=-0.9=-\frac9{10}.\]

\[\left(-\frac52\right)\left(-\frac9{10}\right)=\frac94=2.25.\]

\[12.7:\left(-2\frac12\right)=\frac{127}{10}:\left(-\frac52\right)=-\frac{127}{25}=-5.08.\]

\[2.25-5.08=-2.83.\]

Ответ: \(-2{,}83\).