Question

Answer 1

bài 6:

\(\dfrac{5}{8}:x=\dfrac{25}{14}\\ x=\dfrac{5}{8}:\dfrac{25}{14}\\ x=\dfrac{7}{5}\)

bài 7:

\(=\dfrac{3}{7}\times\left(\dfrac{8}{13}+\dfrac{5}{13}\right)\\ =\dfrac{3}{7}\times1=\dfrac{3}{7}\)

Answer 2

Bài 6:
\(\dfrac{5}{8}:x=2-\dfrac{3}{14}\\ \Rightarrow\dfrac{5}{8}:x=\dfrac{28}{14}-\dfrac{3}{14}\\ \Rightarrow\dfrac{5}{8}:x=\dfrac{25}{14}\\ \Rightarrow x=\dfrac{5}{8}:\dfrac{25}{14}\\ \Rightarrow x=\dfrac{7}{20}\)

Bài 7:

\(\dfrac{3}{7}\times\dfrac{8}{13}+\dfrac{3}{7}\times\dfrac{5}{13}\\ =\dfrac{3}{7}\times\left(\dfrac{8}{13}+\dfrac{5}{13}\right)\\ =\dfrac{3}{7}\times\dfrac{13}{13}\\ =\dfrac{3}{7}\times1\\ =\dfrac{3}{7}\)

Answer 3

6. \(\dfrac{5}{8}:x=2-\dfrac{3}{14}\)

          \(\dfrac{5}{8}:x=\dfrac{25}{14}\)

                 \(x=\dfrac{5}{8}:\dfrac{25}{14}\)

                 \(x=\dfrac{70}{200}\)

7. \(\dfrac{3}{7}.\dfrac{8}{13}+\dfrac{3}{7}.\dfrac{5}{13}=\left(\dfrac{8}{13}+\dfrac{5}{13}\right).\dfrac{7}{3}=1.\dfrac{7}{3}=\dfrac{7}{3}\)