-2 5/6n+1 1/12n - 3 1/2 n = (2 1/18 - 1 1/9) *3 3/5 Помогите пожалуйста буду благодарен !)

Решите задачу:

$-2\frac56n+1\frac1{12}n-3\frac12n=\left(2\frac1{18}-1\frac19\right)\cdot3\frac35\\-\frac{17}6n+\frac{13}{12}n-\frac72n=\left(\frac{37}{18}-\frac{10}9\right)\cdot\frac{18}5\\-\frac{34}{12}n+\frac{13}{12}n-\frac{42}{12}n=\left(\frac{37}{18}-\frac{20}{18}\right)\cdot\frac{18}5\\-\frac{63}{12}n=\frac{17}{18}\cdot\frac{18}5\\-\frac{21}4n=\frac{17}5\\n=\frac{17}5:\left(-\frac{21}{4}\right)=-\frac{17}5\cdot\frac{4}{21}=-\frac{68}{105}$