Question

Giúp mik với. Rõ ràng nha

Answer 1

a,\(\dfrac{2}{5}+\dfrac{1}{10}=\dfrac{4}{10}+\dfrac{1}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)

\(b,3-\dfrac{1}{2}=\dfrac{3}{1}-\dfrac{1}{2}=\dfrac{6}{2}-\dfrac{1}{2}=\dfrac{5}{2}\)

\(c,\dfrac{7}{12}x\dfrac{12}{21}=\dfrac{1}{3}\)

\(d,4:\dfrac{2}{3}=\dfrac{4}{1}:\dfrac{2}{3}=\dfrac{4}{1}x\dfrac{3}{2}=\dfrac{6}{1}=6\)

Answer 2

a) \(\dfrac{2}{5}+\dfrac{1}{10}=\dfrac{4}{10}+\dfrac{1}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)

b) \(3-\dfrac{1}{2}=\dfrac{6}{2}-\dfrac{1}{2}=\dfrac{5}{2}\)

c) \(\dfrac{7}{12}\times\dfrac{12}{21}=\dfrac{7}{21}=\dfrac{1}{3}\)

d) \(4:\dfrac{2}{3}=4\times\dfrac{3}{2}=6\)

Answer 3