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:

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

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

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

11/12=1/4+2/3

15/16=1/8+13/16

15/16 phân tích sai

\(\frac{13}{16}=\frac{1}{2}+\frac{1}{4}+\frac{1}{16}\)

Ta có:\(\frac{13}{16}=\frac{1+4+8}{16}=\frac{1}{16}+\frac{1}{4}+\frac{1}{2}\)

\(\dfrac{11}{16}\) = \(\dfrac{1}{16}\) + \(\dfrac{10}{16}\) = \(\dfrac{1}{16}\) + \(\dfrac{2+8}{2\times8}\) = \(\dfrac{1}{16}\) + \(\dfrac{2}{2\times8}\) + \(\dfrac{8}{2\times8}\) = \(\dfrac{1}{16}\) + \(\dfrac{1}{8}\)+ \(\dfrac{1}{2}\)

\(\dfrac{5}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{4}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{4}{3\times4}\) = \(\dfrac{1}{12}\) + \(\dfrac{1}{3}\)

\(\dfrac{6}{35}\) = \(\dfrac{1}{35}\) + \(\dfrac{5}{35}\) = \(\dfrac{1}{35}\) + \(\dfrac{5}{5\times7}\) = \(\dfrac{1}{35}\) + \(\dfrac{1}{7}\) 

a)11/15=5+3+3/15=5/15+3/15+3/15=1/3+1/5+1/5

b)15/16=4+8+2+2/16=4/16+8/16+2/16+2/16=1/4+1/2+1/8+1/8

\(=\frac{1}{2}+\frac{1}{8}+\frac{1}{16}=\frac{11}{16}\)

a: 13/35=1/5+1/7+1/35

b: 17/63=1/7+1/9+1/63