55555

1, 2006 x 2005 - 1/2004 x 2006 + 2005 = 4411,202002

2,18 x (19191919/21212121 + 88888/99999) = 3,91015873

k mk nha pạn

mk nhanh nhất

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

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

\(=1\)

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

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

= 18 x \(\left(\frac{19.1010101}{21.1010101}+\frac{8.11111}{9.11111}\right)\)= 18 x ( \(\frac{19}{21}+\frac{8}{9}\)) = 9 x 2 ( \(\frac{57+56}{63}\))

= 9 x 2 x \(\frac{113}{63}\)=\(\frac{226}{7}\)

dũng làm chẳng  hiểu gì cả

= 18 ( 19/21 + 8/9)

= 18.113/63

=226/7 

\(=18x\frac{19x1010101}{21x1010101}+\frac{8x11111}{9x11111}=18x\frac{19}{21}+\frac{8}{9}\)

sao khong có kết quả hả bạn

\(18\cdot\left(\frac{19191919}{21212121}+\frac{88888}{99999}\right)\)

\(=18\cdot\left(\frac{19}{21}+\frac{8}{9}\right)\)

\(=18\cdot\frac{113}{63}\)

\(=\frac{678}{21}\approx32,286\)

\(18\left(\frac{19191919}{21212121}+\frac{88888}{99999}\right)\)
\(=18\left(\frac{19}{21}+\frac{8}{9}\right)\)
\(=18\left(\frac{57}{63}+\frac{56}{63}\right)\)
\(=18\left(\frac{113}{63}\right)\)
\(=\frac{3^2.2.113}{3^2.7}\)
\(=\frac{226}{7}\)

\(=18x\left(\frac{19}{21}+\frac{8}{9}\right)\)

\(=18x\frac{113}{63}\)

\(=\frac{226}{7}\)

266/7

18 x ( \(\frac{19}{21}\)+ \(\frac{8}{9}\)) = 18 x \(\frac{35}{21}\)= 30

Câu a:Đáp số 127/128

Câu b:Đáp số 1021/63

a) Đặt A= 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 
2A= 2(1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256) 
     = 1+1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 
=>A =  2A-A =1+1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 -1/2 - 1/4 - 1/8 - 1/16 - 1/32 - 1/64 - 1/128 - 1/256 
=1-1/256 
=255/256

b) = 18 - (19/21 + 8/9) = 18 - 113/63 = 1021/63

a) Đặt A= 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 
2A= 2(1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256) 
     = 1+1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 
=>A =  2A-A =1+1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 -1/2 - 1/4 - 1/8 - 1/16 - 1/32 - 1/64 - 1/128 - 1/256 
=1-1/256 
=255/256

b) sai đề