30 5/6-(7 1/3++2 1/4):0,25

Решите задачу:

$30 \frac{5}{6} -(7 \frac{1}{3} +2 \frac{1}{4} ): \frac{1}{4} =-7.5\\\\1) 7 \frac{1}{3} +2 \frac{1}{4}= 7 \frac{4}{12} +2 \frac{3}{12} =9 \frac{7}{12} = \frac{115}{12} \\ \\ 2) \frac{115}{12} : \frac{1}{4} = \frac{115*4}{12} = \frac{115}{3} =38 \frac{1}{3} \\ \\ 3)30 \frac{5}{6} -38 \frac{1}{3} =-(38 \frac{1}{3} -30 \frac{5}{6} )=-(38 \frac{2}{6} -30 \frac{5}{6} )=\\\\=-(37 \frac{8}{6} -30 \frac{5}{6} )=-(7 \frac{3}{6} )=-7 \frac{1}{2} =-7 \frac{5}{10} =-7.5$