Помогите только 12 задания

А) $7 \frac{16}{35} -( 3\frac{11}{35}+ 4\frac{1}{56} )=0,125$

$1) 3\frac{11}{35} + 4\frac{1}{56} = \frac{116}{35} +\frac{225}{56} = \frac{8*116+5*225}{280}= \frac{928+1125}{280}= \frac{2053}{280}$

$2)7 \frac{16}{35} - \frac{2053}{280} = \frac{261}{35} - \frac{2053}{280} = \frac{2088-2053}{280} = \frac{35}{280} = \frac{1}{8} =0,125$

$b) 7+ 1 \frac{29}{40} +2 \frac{17}{30} =11 \frac{7}{24}$

$1)7+1 \frac{29}{40} = \frac{7}{1} + \frac{69}{40} = \frac{349}{40}$

$2) \frac{349}{40} +2 \frac{17}{30} = \frac{349}{40} + \frac{77}{30} = \frac{1047+308}{120} = \frac{1355}{120}= \frac{271}{24} =11 \frac{7}{24}$

$c) 8\frac{5}{12} + \frac{5}{6}-5 \frac{3}{4} -2 \frac{1}{2} = \frac{101}{12} + \frac{5}{6} - \frac{23}{4} - \frac{5}{2} = \frac{101+2*5-3*23-6*5}{12} = \frac{12}{12} =1$