Question

Tính giá trị các biểu thức sau : 

a, 2\(\dfrac{3}{5}\) + 1\(\dfrac{1}{4}\) x 2\(\dfrac{2}{3}\) =                                  b, 5\(\dfrac{1}{7}\) - 2\(\dfrac{4}{5}\) : 1\(\dfrac{1}{5}\) =                          c, 4\(\dfrac{1}{4}\) - 2\(\dfrac{5}{8}\) x \(\dfrac{16}{39}\) =

Answer 1

a, \(=\dfrac{13}{5}+\dfrac{5}{4}.\dfrac{8}{3}=\dfrac{13}{5}+\dfrac{10}{3}=\dfrac{89}{15}\)

b, \(=\dfrac{36}{7}-\dfrac{14}{5}:\dfrac{6}{5}=\dfrac{36}{7}-\dfrac{7}{3}=\dfrac{59}{21}\)

c, \(=\dfrac{17}{4}-\dfrac{21}{8}.\dfrac{16}{39}=\dfrac{17}{4}-\dfrac{42}{39}=\dfrac{165}{52}\)

Answer 2

a. \(2\dfrac{3}{5}+1\dfrac{1}{4} . 2\dfrac{2}{3}=\dfrac{13}{5}+\dfrac{5}{4} . \dfrac{8}{3}=\dfrac{13}{5}+\dfrac{10}{3}=\dfrac{89}{15}\)

b. \(5\dfrac{1}{7}-2\dfrac{4}{5} : 1\dfrac{1}{5}=\dfrac{36}{7}-\dfrac{14}{5} : \dfrac{6}{5}=\dfrac{36}{7}-\dfrac{7}{3}=\dfrac{59}{21}\)

c. \(4\dfrac{1}{4}-2\dfrac{5}{8} . \dfrac{16}{39}=\dfrac{17}{4}-\dfrac{21}{8} . \dfrac{16}{39}=\dfrac{17}{4}-\dfrac{14}{13}=\dfrac{165}{52}\)

Answer 3

a) \(2\dfrac{3}{5}+1\dfrac{1}{4}\times2\dfrac{2}{3}\)

\(=\dfrac{13}{5}+\dfrac{5}{4}\times\dfrac{8}{3}\)

\(=\dfrac{13}{5}+\dfrac{10}{3}\)

\(=\dfrac{89}{15}\)

b) \(5\dfrac{1}{7}-2\dfrac{4}{5}:1\dfrac{1}{5}\)

\(=\dfrac{36}{7}-\dfrac{14}{5}:\dfrac{6}{5}\)

\(=\dfrac{36}{7}-\dfrac{7}{3}\)

\(=\dfrac{59}{21}\)

c) \(4\dfrac{1}{4}-2\dfrac{5}{8}\times\dfrac{16}{39}\)

\(=\dfrac{17}{4}-\dfrac{21}{8}\times\dfrac{16}{39}\)

\(=\dfrac{17}{4}-\dfrac{14}{13}\)

\(=\dfrac{165}{52}\)