Question

tính bằng cách thuân tiện : 5/15 + 3/12 + 4/20 +18/27 +12/16 + 20/25

Answer 1

\(\frac{5}{15}+\frac{3}{12}+\frac{4}{20}+\frac{18}{27}+\frac{12}{16}+\frac{30}{25}\)

\(=\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{2}{3}+\frac{3}{4}+\frac{4}{5}\)

\(=\left(\frac{1}{3}+\frac{2}{3}\right)+\left(\frac{1}{4}+\frac{3}{4}\right)+\left(\frac{1}{5}+\frac{4}{5}\right)\)

\(=1+1+1\)

\(=3\)