Question

Tính hợp lý:5/6 • 1/3 + 1/2 • 3/4 •5/3

 

Answer 1

=5/18+3/8*5/3

=5/18+5/8

=65/72

Answer 2

\(\dfrac{5}{6}\cdot\dfrac{1}{3}+\dfrac{1}{2}\cdot\dfrac{3}{4}\cdot\dfrac{5}{3}\)

\(=\dfrac{5\cdot1}{6\cdot3}+\dfrac{1}{2}\cdot\dfrac{3\cdot5}{4\cdot3}\)

\(=\dfrac{5}{18}+\dfrac{1}{2}\cdot\dfrac{15}{12}\)

\(=\dfrac{5}{18}+\dfrac{1}{2}\cdot\dfrac{5}{4}\)

\(=\dfrac{5}{18}+\dfrac{1\cdot5}{2\cdot8}\)

\(=\dfrac{5}{18}+\dfrac{5}{8}\)

\(=\dfrac{65}{72}\)