\(\dfrac{7}{12}=\dfrac{3}{12}+\dfrac{4}{12}=\dfrac{1}{4}+\dfrac{1}{3}\)

\(\dfrac{13}{27}=\dfrac{9}{27}+\dfrac{4}{27}=\dfrac{1}{3}+\dfrac{4}{27}\)

\(\dfrac{7}{12}\) = \(\dfrac{1+6}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{6}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{1}{2}\)

\(\dfrac{7}{12}\) = \(\dfrac{3+4}{12}\) = \(\dfrac{3}{12}\) + \(\dfrac{4}{12}\) = \(\dfrac{1}{4}\) + \(\dfrac{1}{3}\)

\(\dfrac{13}{27}\) = \(\dfrac{1+12}{27}\) = \(\dfrac{1}{27}\) + \(\dfrac{12}{27}\) = \(\dfrac{1}{27}\) + \(\dfrac{4}{9}\)

\(\dfrac{13}{27}\) = \(\dfrac{4+9}{27}\) = \(\dfrac{4}{27}\) + \(\dfrac{9}{27}\) = \(\dfrac{4}{27}\) + \(\dfrac{1}{3}\)

\(\dfrac{13}{27}\) = \(\dfrac{6+7}{27}\) = \(\dfrac{6}{27}\) + \(\dfrac{7}{27}\) = \(\dfrac{2}{9}\) +  \(\dfrac{7}{27}\)

1/18+2/3

a. 5/12=1/6+1/4

b.8/27=1/9+5/27

B

`=>B`

a,7/12=1/4+1/3

a: \(\frac{13}{27}=\frac{1}{27}+\frac{12}{27}=\frac{1}{27}+\frac49=\frac{1}{27}+\frac{3+1}{9}=\frac{1}{27}+\frac39+\frac19\)

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

b: \(\frac{15}{16}=\frac{1}{16}+\frac{14}{16}\)

\(=\frac{1}{16}+\frac78=\frac{1}{16}+\frac{4+3}{8}=\frac{1}{16}+\frac48+\frac38\)

\(=\frac{1}{16}+\frac12+\frac{2+1}{8}=\frac{1}{16}+\frac12+\frac14+\frac18\)

c: \(\frac{39}{54}=\frac{38+1}{54}=\frac{38}{54}+\frac{1}{54}\)

\(=\frac{1}{54}+\frac{19}{27}=\frac{1}{54}+\frac{1}{27}+\frac{18}{27}\)

\(=\frac{1}{54}+\frac{1}{27}+\frac23=\frac{1}{54}+\frac{1}{27}+\frac46=\frac{1}{54}+\frac{1}{27}+\frac36+\frac16\)

\(=\frac{1}{54}+\frac{1}{27}+\frac16+\frac12\)

d: \(\frac{13}{42}=\frac{6+7}{42}=\frac{6}{42}+\frac{7}{42}=\frac17+\frac16\)

a, 18/54 = 1/3 

b, 1/3 = 1/5 +2/15

a) \(\frac{18}{54}=\frac{1}{3}\)

b) \(\frac{18}{54}=\frac{1}{5}+\frac{2}{15}\)

~Học tốt~

7/12=1/3+1/4

10/21=1/3+1/7

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