Question

Помогите срочно
Отдам все баллы!

Answer 1

$- frac{2}{7} + frac{5}{42} = - (6times frac{2}{7} ) + frac{5}{42} = \ - frac{12}{42} + frac{5}{42 } = - frac{7}{42} = - frac{1}{6}$
$frac{13}{14} + ( - frac{11}{21}) = ( 3 times frac{13}{14} ) + ( - (2 times frac{11}{21})) = \ frac{39}{42} + ( - frac{22}{42}) = frac{17}{42}$
$5frac{3}{4} + ( - 5 frac{5}{6} ) = (3 times frac{23}{4} ) + ( - (2 times frac{35}{6} )) = \ frac{69}{12} + ( - frac{70}{12}) = - frac{1}{12}$
$- frac{4}{9} + 1 = - frac{4}{9} + frac{9}{9} = frac{5}{9}$
$1 frac{3}{4} + ( - 8) = 1 frac{3}{4} + ( - 7 frac{4}{4}) = -6frac{1}{4}$
$- frac{5}{6} + frac{2}{9} = - ( 3 times frac{5}{6} ) + (2 times frac{2}{9}) = \ (-frac{15}{18}) + frac{4}{18} = -frac{11}{18}$
$7 frac{14}{22} + ( - 8 frac{11}{11} ) = 7 frac{14}{22} + ( - (2 times 8frac{11}{11} ) = \ 7 frac{14}{22} + ( - 8 frac{22}{22} ) = - 1 frac{8}{22} = - 1frac{4}{11}$

Answer 2

Пожалуйста отметь как лучший ответ

Answer 3

 1)2/7  +  5/42 = (-2 × 6  +  5 × 1)/42 = -12/42  +  5/42 =  - 7/42 = - 1/6
2)- 4/9 + 1 = (-4 × 1  +  1 × 9)/9 = -4/9  +  9/9 =  5/9
3)13/14 + ( - 11/21 ) = 13/14 - 11/21 = (13 × 3 - 11 × 2)/42 = 39/42 - 22/42 = 17/42
4)5 3/4 + ( - 5 5/6 ) = 5 3/4  -  5 5/6 = 23/4  -  35/6 = (23 × 3  -  35 × 2)/12 = 69/12  -  70/12 =  - 1/12
5)1 3/4 + ( - 8) = 1 3/4 - 8 = 7/4 - 8 =(7 × 1 - 8 × 4)/4 = 7/4 -32/4 =  - 25/4 = - 6 1/4
6)- 5/6 + 2/9 = -5 × 3  +  2 × 2)/18 = (-15  +  4)/18 =  - 11/18
7)7 14/22  + 9 - 8 11/11 ) = 7 14/22  - 8 11/11 = 84/11 - 9 =(84 × 1 - 9 × 11)/11 = 84/11  -  99/11 =  - 15/11 = - 1 4/11