Question

81. Aflati valoarea expresiei:a) 1 3/25×2 1/7-2 1/9×27/95; b)4 7/1×1 3/11+1 1/15×1 11/64​

Answer 1

Răspuns:

Explicație pas cu pas:

a)

$1\dfrac{3}{25} \cdot 2\dfrac{1}{7} - 2\dfrac{1}{9} \cdot \dfrac{27}{95} = \dfrac{1*25+3}{25} \cdot \dfrac{2*7+1}{7} - \dfrac{2*9+1}{9} \cdot \dfrac{27}{95} = \dfrac{28}{25} \cdot \dfrac{15}{7} - \dfrac{19}{9} \cdot \dfrac{27}{95} = \dfrac{4}{5} \cdot \dfrac{3}{1} - \dfrac{1}{1} \cdot \dfrac{3}{5} = \dfrac{12-3}{5} = \dfrac{9}{5}$

b)

$4\dfrac{7}{1} \cdot 1\dfrac{3}{11} + 1\dfrac{1}{15} \cdot 1\dfrac{11}{64} = \dfrac{4*1+7}{1} \cdot \dfrac{1*11+3}{11} + \dfrac{1*15+1}{15} \cdot \dfrac{1*64+11}{64} = \dfrac{11}{1} \cdot \dfrac{14}{11} + \dfrac{16}{15} \cdot \dfrac{75}{64} = \dfrac{1}{1} \cdot \dfrac{14}{1} + \dfrac{1}{1} \cdot \dfrac{5}{4} = 14 + \dfrac{5}{4} = 14\dfrac{5}{4}$