Question

Tính giá trị của biểu thức:
A) 5/6 x7/12 + 5/12 x 5/6 +1/6
B) ( 8/15 x 3/4 x 5/4) : 7/8

Answer 1

\(a,\dfrac{5}{6}\times\dfrac{7}{12}+\dfrac{5}{12}\times\dfrac{5}{6}+\dfrac{1}{6}=\dfrac{5}{6}\times\left(\dfrac{7}{12}+\dfrac{5}{12}\right)+\dfrac{1}{6}=\dfrac{5}{6}\times\dfrac{12}{12}+\dfrac{1}{6}=\dfrac{5}{6}+\dfrac{1}{6}=\dfrac{6}{6}=1\\ ----------\\ b,\left(\dfrac{8}{15}\times\dfrac{3}{4}\times\dfrac{5}{4}\right):\dfrac{7}{8}=\left(\dfrac{2}{5}\times\dfrac{5}{4}\right):\dfrac{7}{8}=\dfrac{2}{4}:\dfrac{7}{8}=\dfrac{1}{2}:\dfrac{7}{8}=\dfrac{1}{2}\times\dfrac{8}{7}=\dfrac{4}{7}\)