Question

[lu nguyễn]

TÍNH:

\(\dfrac{27}{10}+\dfrac{291}{100}+\dfrac{38}{100}+\dfrac{547}{1000}\dfrac{893}{10000}\)

TÍNH NHANH

a, \(\dfrac{2006\times2005-1}{2004\times2006+2005}\)\

b, \(18\times\left(\dfrac{19191919+88888}{21212121+99999}\right)\)

Answer 1

[Lê Gia Bảo]

\(\dfrac{2006\times2005-1}{2004\times2006+2005}=\dfrac{2006\times\left(2004+1\right)-1}{2004\times2006+2005}\)

\(=\dfrac{2004\times2006+2006-1}{2004\times2006+2005}=\dfrac{2004\times2006+2005}{2004\times2006+2005}\)

\(=1\)

Answer 2

[Lê Gia Bảo]

\(18\times\left(\dfrac{19191919+88888}{21212121+99999}\right)=18\times\left(\dfrac{19}{21}+\dfrac{8}{9}\right)\)

\(=18\times\dfrac{113}{63}=\dfrac{226}{7}=32\dfrac{2}{7}\)