Question

[Nguyễn Thiên Hương]

tính

 b)   (7/27+8/27)+12/27          27+(8/27+12/27)          c) (4/9+8/9)+3/9            4/9+(8/9+3/9)

Answer 1

[๒ạςђ ภђเêภ♕]

b) \(\left(\frac{7}{27}+\frac{8}{27}\right)+\frac{12}{27}\)

\(=\frac{7}{27}+\frac{8}{27}+\frac{12}{27}\)

\(=\frac{27}{27}=1\)

\(27+\left(\frac{8}{27}+\frac{12}{27}\right)\)

\(=27+\frac{20}{27}\)

\(=\frac{729}{27}\)

c) \(\left(\frac{4}{9}+\frac{8}{9}\right)+\frac{3}{9}\)

\(=\frac{4}{9}+\frac{8}{9}+\frac{3}{9}\)

\(=\frac{15}{9}=\frac{5}{3}\)

\(\frac{4}{9}+\left(\frac{8}{9}+\frac{3}{9}\right)\)

\(=\frac{15}{9}=\frac{5}{3}\)

#H

Answer 2

[Dương Đức Hà]

na ní vãi