Question

Виконайте додавання: 1)-17,9 +0; 2)-0,68 +(-0,32); 3) -2/3+11/12;4) 5/21+(-3/14);5) -2 4/9+(-3 1/2);6)-4 16+2 1/5.​

Answer 1

Ответ:

$1) \: - 17.9$

$2) \: - 1$

$3) \: - \frac{8 + 11}{12} = \frac{3}{12} = \frac{1}{4}$

$4) \: \frac{5}{21} - \frac{3}{14} = \frac{10 - 9}{42} = \frac{1}{42}$

$5) \: - 2\frac{4}{9} - 3 \frac{1}{2} = - (2 \frac{4}{9} + 3 \frac{1}{2} ) = - ((2 + 3) + ( \frac{4}{9} + \frac{1}{2} )) = - (5 + ( \frac{8 + 9}{18}) = - (5 + \frac{17}{18} ) = - 5 \frac{17}{18}$

$6) \: - \frac{25}{6} + \frac{11}{5} = \frac{ - 125 + 66}{30} = \frac{ - 59}{30} = - \frac{59}{30}$