ПОМОГИТЕ ПРОШУ!!!! ПОМОГИИТЕЕ!!! ПО ДЕЙСТВИЯМ !!!! 1) (-12,4 + 8,9)* 1 3/7 = 2)(2 3/8 - 1...

1) (-12,4 + 8,9)* 1 3/7 =-2,45
1.-12,4+8,9=-3,5
$2. - 3.5 \div 1 \frac{3}{7} = - 3 \frac{1}{2} \div \frac{10}{7} = - \frac{7 \times 7}{2 \times 10} = - \frac{49}{20} = - 2.45$
2)(2 3/8 - 1 5/6) :(-1 5 /8) =11/39
$1...2 \frac{3}{8} - 1 \frac{5}{6} = \frac{9 - 20}{24} = - \frac{11}{24}$
$- \frac{11}{24} \div ( - 1 \frac{5}{8} ) = \frac{11 \times 8}{24 \times 13} = \frac{11}{39}$