a,\(\frac{2015.2016+2015-1}{2014+2015.2016}=\frac{2015.2016+2014}{2014+2015.2016}=1\)\(1\)

b,\(=1-\frac{1}{5}+\frac{1}{5}...-\frac{1}{2011}+\frac{1}{2011}-\frac{1}{2015}=1-\frac{1}{2015}=\frac{2014}{2015}\)

c,\(=\frac{12}{35}+\frac{12}{35}+\frac{12}{35}+\frac{12}{35}=\frac{12}{35}.4=\frac{48}{35}\)

48/35 nha

b>=1-1/5+1/5-1/9+...+1/2011-1/2015

 =1-1/2015

=2014/2015

c>=12/35+12/35+12/35+12/35

=12/35x4

=48/35

Ta có : 1212/3535=12/35 ; 1212/9999=12/99

Từ đề bài => = 12/15 +12/35 +12/63 +12/99

                    = 6 x ( 2/15 + 2/35 +2/63+2/99 )

                    = 6 x ( 2/3x5 + ....+ 2/9x11)

                    = 6 x ( 1/3 - 1/5 +....+1/9 - 1/11)

                    = 6 x ( 1/3 - 1/11)

                    = 6 x 8/33 = 48/33

ai giúp zới. mai đi hok rùi

48/33

12/15+12/35+12/63+4/33

=4/3+4/33

=16/11

bạn có thể giải thích cho mk luôn dc k ban

a)Ta có : \(\dfrac{1212}{1414}=\dfrac{12.101}{14.101}=\dfrac{12}{14}\)

\(\dfrac{121212}{242424}=\dfrac{12.10101}{24.10101}=\dfrac{12}{24}\)

Vậy \(\dfrac{12}{24}=\dfrac{1212}{2424}=\dfrac{121212}{242424}\)

Ta có : \(\dfrac{2424}{3535}=\dfrac{24.101}{35.101}=\dfrac{24}{35}\)

\(\dfrac{242424}{353535}=\dfrac{24.10101}{35.10101}=\dfrac{24}{35}\)

Vậy \(\dfrac{24}{35}=\dfrac{2424}{3535}=\dfrac{242424}{353535}\)

Ta có : \(\dfrac{224466}{255075}=\dfrac{22.10203}{25.10203}=\dfrac{22}{25}\)

Vậy \(\dfrac{22}{25}=\dfrac{224466}{255075}\)

giup toi

\(\frac{3}{4}x-14\frac{2}{3}:\left(\frac{11}{15}+\frac{1111}{3535}+\frac{111111}{636363}\right)=12\)

\(\frac{3}{4}x-\frac{44}{3}:\left(\frac{11}{15}+\frac{11}{35}+\frac{11}{63}\right)=12\)

\(\frac{3}{4}x-\frac{44}{3}:\frac{11}{9}=12\)

\(\frac{3}{4}x-12=12\)

\(\frac{3}{4}x=12+12\)

\(\frac{3}{4}x=24\)

\(x=24:\frac{3}{4}\)

\(x=32\)

vậy \(x=32\)

ket qua bang 32

C

C

Chọn C