8/15 = 1/5 + 1/3

8./15 = 1/5 + 1/3 

8/15 = 4/15 + 4/15 = 1/15 + 7/15

VD:8/15=1/3+1/5

7/15=1/15+2/5=2/15+1/3=1/5+4/15

\(\frac{5}{8}=\frac{2}{8}+\frac{3}{8}=\frac{1}{8}+\frac{1}{2}\)

C1:3/8+1/2

C2:1/8+1/2

\(\frac{13}{15}\) = \(\frac{1}{5}\) + \(\frac{2}{3}\) = \(\frac{2}{5}\) + \(\frac{7}{15}\) = \(\frac{1}{3}\) + \(\frac{8}{15}\) 

 \(\frac{23}{20}\) = \(\frac{9}{10}\) + \(\frac{1}{4}\) = \(\frac{1}{2}\) + \(\frac{13}{20}\) = \(\frac{1}{5}\) + \(\frac{19}{20}\) = \(\frac{3}{10}\) + \(\frac{17}{20}\) = ....

 Học tốt !

Bài 2:

\(\frac{13}{36}=\frac{1+5+7}{36}=\frac{1}{36}+\frac{5}{36}+\frac{7}{36}\)

\(\frac{31}{60}=\frac{1+23+7}{60}=\frac{1}{60}+\frac{23}{60}+\frac{7}{60}\)

Bài 1:

\(\frac{25}{27}=\frac{1+3+9+3+9}{27}=\frac{1}{27}+\frac19+\frac13+\frac19+\frac13\)

\(\frac{15}{16}=\frac{8+7}{16}=\frac12+\frac{7}{16}=\frac12+\frac{4+3}{16}=\frac12+\frac14+\frac{3}{16}\)

\(=\frac12+\frac14+\frac{2+1}{16}=\frac12+\frac14+\frac18+\frac{1}{16}\)

\(\dfrac{7}{15}=\dfrac{8}{15}+\dfrac{-1}{15}\)

10/27: 1/27+7/27+2/27

13/12: 1/12+7/12+5/12

15/8:7/8+3/8+5/8

10/27 = 1/27+2/27+7/27

13/12 = 1/12+5/12+7/12

15/8 =  3/8+5/8+7/8

1/5 + 4/15