1/20+1/4+2/5=3/10+2/5=7/10
=>1/20+1/4+2/5=7/10
Vậy 1/20+1/4+2/5=7/10
\(\frac{1}{20}\)+\(\frac{1}{4}\)+\(\frac{2}{5}\)=\(\frac{7}{10}\)=0,7
\(\frac{1}{20}+\frac{1}{4}+\frac{2}{5}=\frac{7}{10}\)
1/20 + 1/4 + 1/5 = 1/20 + 5/20 + 4/20= 1+4+5/20 = 10/20 = 1/2