Question

[oOo Lê Ánh Hằng oOo]

Thực hiện các phép tính sau

a) 1\(\frac{1}{2}\)+ 2 \(\frac{1}{3}\)+ 3 \(\frac{1}{6}\) - 5 = 

b) 2 \(\frac{2}{3}\)x 3 \(\frac{3}{4}\): 4 \(\frac{4}{5}\) = 

c) 4 \(\frac{1}{5}\) + 5 \(\frac{1}{3}\) - 2 \(\frac{2}{3}\) x 3 \(\frac{1}{5}\) + \(\frac{9}{25}\) : \(\frac{9}{20}\) = 

Answer 1

[Mỹ Anh]

a ) \(1\frac{1}{2}+2\frac{1}{3}+3\frac{1}{6}-5\)

\(=\frac{3}{2}+\frac{7}{3}+\frac{19}{6}-\frac{5}{1}\)

\(=\frac{9}{6}+\frac{14}{6}+\frac{19}{6}-\frac{30}{6}\)

\(=\frac{23}{6}+\frac{19}{6}-\frac{30}{6}\)

\(=\frac{42}{6}-\frac{30}{6}\)

\(=\frac{12}{6}=2\)

b ) \(2\frac{2}{3}\times3\frac{3}{4}\div4\frac{4}{5}\)

\(=\frac{8}{3}\times\frac{15}{4}\div\frac{24}{5}\)

\(=\frac{120}{12}\div\frac{24}{5}\)

\(=\frac{120}{12}\times\frac{5}{24}\)

\(=\frac{600}{288}=\frac{25}{12}\)

c ) \(4\frac{1}{5}+5\frac{1}{3}-2\frac{2}{3}\times3\frac{1}{5}+\frac{9}{25}\div\frac{9}{20}\)

\(=\frac{21}{5}+\frac{16}{3}-\frac{8}{3}\times\frac{16}{5}+\frac{9}{25}\div\frac{9}{20}\)

\(=\frac{63}{15}+\frac{80}{15}-\frac{128}{15}+\frac{9}{25}\times\frac{20}{9}\)

\(=\frac{143}{15}-\frac{128}{15}+\frac{180}{225}\)

\(=\frac{15}{15}+\frac{12}{15}\)

\(=\frac{27}{15}=\frac{9}{5}\)