Question

упростите выражение и найдите его значение 1) 4/7b + 5/21b - 2/3 , если b = 2 1/3

Answer 1

4/7+5/21 = 17/21
17/21×2 1/3= 1 8/9
1 8/9 - 2/3 = 1 2/9

Answer 2

$frac{4}{7}b+ frac{5}{21}b- frac{2}{3}= frac{12}{21}b+ frac{5}{21}b- frac{2}{3}= frac{17}{21}b- frac{14}{21} \b=2 frac{1}{3}\frac{17}{21}* frac{7}{3}- frac{2}{3}= frac{17}{9}- frac{6}{9}= frac{11}{9}=1 frac{2}{9}$