Question

[Hoàng Ninh]

Tính bằng cách thuận tiện nhất:

a,\(\frac{3}{7}\)x  \(\frac{5}{6}\)+  \(\frac{5}{6}\)x   \(\frac{4}{7}\)

b,\(\frac{1}{6}\):  \(\frac{4}{5}\)+  \(\frac{1}{8}\):   \(\frac{4}{5}\)

c,  \(\frac{1}{6}\): \(\frac{4}{5}\)-  \(\frac{1}{8}\):  \(\frac{4}{5}\)

Lời giải đúng nhé

Answer 1

[Đỗ Thị Thanh Nguyên]

\(a.\frac{3}{7}.\frac{5}{6}+\frac{5}{6}.\frac{4}{7}=\left(\frac{3}{7}+\frac{4}{7}\right).\frac{5}{6}=1.\frac{5}{6}=\frac{5}{6}\)

\(b.\frac{1}{6}:\frac{4}{5}+\frac{1}{8}:\frac{4}{5}=\left(\frac{1}{6}+\frac{1}{8}\right):\frac{4}{5}=\left(\frac{4}{24}+\frac{3}{24}\right):\frac{4}{5}=\frac{7}{24}:\frac{4}{5}=\frac{7.5}{24.4}\)\(=\frac{35}{96}\)

\(c.\frac{1}{6}:\frac{4}{5}-\frac{1}{8}:\frac{4}{5}=\left(\frac{1}{6}-\frac{1}{8}\right):\frac{4}{5}=\left(\frac{4}{24}-\frac{3}{24}\right):\frac{4}{5}\)\(=\frac{1}{24}:\frac{4}{5}=\frac{1.5}{24.4}=\frac{5}{96}\)

Answer 2

[๖ۣۜƝƘ☆☨☈ầnミ★♄☯àngミ★✔ίệ☨★彡]

a) \(\frac{3}{7}\cdot\frac{5}{6}+\frac{5}{6}\cdot\frac{4}{7}\)

\(=\left(\frac{3}{7}+\frac{4}{7}\right)\cdot\frac{5}{6}\)

\(=1\cdot\frac{5}{6}\)

\(=\frac{5}{6}\)

b) \(\frac{1}{6}:\frac{4}{5}+\frac{1}{8}:\frac{4}{5}\)

\(=\left(\frac{1}{6}+\frac{1}{8}\right):\frac{4}{5}\)

\(=\frac{7}{24}:\frac{4}{5}\)

\(=\frac{35}{96}\)

c) \(\frac{1}{6}:\frac{4}{5}-\frac{1}{8}:\frac{4}{5}\)

\(=\left(\frac{1}{6}-\frac{1}{8}\right):\frac{4}{5}\)

\(=\frac{1}{24}:\frac{4}{5}\)

\(=\frac{5}{96}\)