\[\boxed{\text{165\ (165).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[- 0,5 \cdot (7b - 12a) - (8,4a - 14b) =\]
\[= (14b - 3,5b) - (8,4a - 6a) =\]
\[= 10,5b - 2,4a\]
\[при\ a = - 10;\ \ b = - 6:\]
\[10,5b - 2,4a =\]
\[= 10,5 \bullet ( - 6) - 2,4 \bullet ( - 10) =\]
\[= - 63 + 24 = - 39.\]