5целых7/15-(7целых1/12-(4целых29/60-(2целых1/5-1целая5/6))) помогите пожалуйста

Решите задачу:

$5\frac{7}{15}-( 7\frac{1}{12}-(4 \frac{29}{60} -(2\frac{1}{5} -1 \frac{5}{6})) )= 2,5$

$1) 2 \frac{1}{5} -1\frac{5}{6} = \frac{2*5+1}{5} - \frac{1*6+5}{6} = \frac{11}{5} -\frac{11}{6} = \frac{6*11-5*11}{30} =\frac{66-55}{30} = \frac{11}{30}$

$2) 4\frac{29}{60}- \frac{11}{30} = \frac{4*60+29}{60} - \frac{2*11}{60} = \frac{269}{60} - \frac{22}{60} = \frac{247}{60}$

$3) 7 \frac{1}{12}- \frac{247}{60}= \frac{7*12+1}{12}- \frac{247}{60} = \frac{85}{12}- \frac{247}{60} = \frac{5*85 - 247}{60} = \frac{425-247}{60} = \frac{178}{60}$

$4) 5 \frac{7}{15} - \frac{178}{60} = \frac{5*15+7}{15} - \frac{178}{60} = \frac{82}{15} - \frac{178}{60} = \frac{4*82-178}{60} = \frac{328-178}{60}= \frac{150}{60}= 2,5$