Найди значение выражения: 12 1/4-(8+4 3/8)*(3 2/9-2 5/11). Created by adela. matematika-ru

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таня90

12 1/4 - (8+4 3/8) *(3 2/9 - 2 5/11)=

49/4 - (8+35/8)*(29/9 - 27/11)=

49/4 - 99/8 * 76/99= 49/4 - 19/2= 11/4 = 2 3/4

5 votes Thanks 11

Svet1ana

$12\frac{1}{4}-(8+4\frac{3}{8})\cdot(3\frac{2}{9}-2\frac{5}{11})=2\frac{3}{4}$

1) $8+4\frac{3}{8}=8+\frac{35}{8}=\frac{64+35}{8}=\frac{99}{8}=12\frac{3}{8}$

2) $3\frac{2}{9}-2\frac{5}{11}=\frac{29}{9}-\frac{27}{11}=\frac{319-243}{99}=\frac{76}{99}$

3) $12\frac{3}{8}\cdot\frac{76}{99}=\frac{99}{8}\cdot\frac{76}{99}=\frac{76}{8}=\frac{19}{2}= 9\frac{1}{2}$

4) $12\frac{1}{4}-9\frac{1}{2}=\frac{49}{4}-\frac{19}{2}=\frac{49-38}{4}=\frac{11}{4}=2\frac{3}{4}$

7 votes Thanks 11