Упростите выражение: дробь с-6/8+12с - дробь 2с-7/15с+10

$\frac{c-6}{8+12c}-\frac{2c-7}{1c+10}=\frac{c-6}{4\left(3c+2\right)}-\frac{2c-7}{5\left(3c+2\right)} = \frac{\left(c-6\right)\cdot \:5}{20\left(3c+2\right)}-\frac{\left(2c-7\right)\cdot \:4}{20\left(3c+2\right)}=$
$=\frac{5\left(c-6\right)-4\left(2c-7\right)}{20\left(3c+2\right)}=\frac{-3c-2}{20\left(3c+2\right)}=\frac{-\left(3c+2\right)}{20\left(3c+2\right)}=\frac{-\left(3c+2\right)}{20\left(3c+2\right)}=-\frac{1}{20}=-0,05$