Question

Tính bằng cách hợp lí :

a,  1/5 x 2/9 : 1/15                                                   b, 4/15 x 7/15 x 5/4

c,   21/23 x 5/11 x 44/                                              d, 26 x 13/42 : 13

Giải hộ tí tick

Answer 1

a,\(\frac{1}{5}\times\frac{2}{9}\div\frac{1}{15}\)

\(=\frac{1}{5}\times\frac{2}{9}\times15\)

\(=\left(\frac{1}{5}\times15\right)\times\frac{2}{9}\)

\(=3\times\frac{2}{9}\)

\(=\frac{2}{3}\)

b\(\frac{4}{15}\times\frac{7}{15}\times\frac{5}{4}\)

\(=\left(\frac{4}{15}\times\frac{5}{4}\right)\times\frac{7}{15}\)

\(=\frac{1}{3}\times\frac{7}{15}\)

\(=\frac{7}{45}\)

c,\(\frac{21}{23}\times\frac{5}{11}\times\frac{44}{?}\)

d,\(26\times\frac{13}{42}\div13\)

\(=\left(26\div13\right)\times\frac{13}{42}\)

\(=2\times\frac{13}{42}\)

\(=\frac{13}{21}\)

Answer 2

ờ ờ .......................... hong bt

Answer 3

21/23 x 5/11x 44/35