ve 2 bang 0 

con ve 1 o can tinh du co lon 

vi 0 nhan bao nhieu cung bang o

\(=\)\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)\times\left(\frac{4}{12}-\frac{3}{12}-\frac{1}{12}\right)\)

\(=\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)\times0\)

\(=0\)

\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right).\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)

=\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right).\left(\frac{4}{12}-\frac{3}{12}-\frac{1}{12}\right)\)

=\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right).\left(\frac{1}{12}-\frac{1}{12}\right)\)

=\(\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right).0\)

=0

1) \(5\frac{2}{7}\).\(\frac{8}{11}\)+\(5\frac{2}{7}.\frac{5}{11}+5\frac{2}{7}.\frac{-2}{11}\)

= \(5\frac{2}{7}\).[\(\frac{8}{11}+\frac{5}{11}+\frac{-2}{11}\)]

= \(5\frac{2}{7}\).1

=\(5\frac{2}{7}\)

2)

5 2/7.8/9+5 2/7.5/11-5 2/7.2/11

=5 2/7.(8/11+5/11+2/11)

=5 2/7.15/11

=240/77.

(67/111+2/33-15/117).(1/3-1/4-1/12)

=811/1221.1/12

=811/14652

dễ mà

trừ đi rùi rút gọn

\(C=\left(\frac{3}{5}-\frac{4}{15}\right).\left(\frac{2}{7}-\frac{3}{14}\right)-\left(\frac{5}{9}-\frac{7}{27}\right).\left(1-\frac{3}{5}\right)+\left(1-\frac{11}{12}\right).\left(1+\frac{1}{12}\right)\)

\(C=\left(\frac{9}{15}-\frac{4}{15}\right).\left(\frac{4}{14}-\frac{3}{14}\right)-\left(\frac{15}{27}-\frac{7}{27}\right).\left(\frac{5}{5}-\frac{3}{5}\right)+\left(\frac{12}{12}-\frac{11}{12}\right).\left(\frac{12}{12}+\frac{1}{12}\right)\)

\(C=\frac{5}{15}.\frac{1}{14}.\frac{8}{27}.\frac{2}{5}.\frac{1}{12}.\frac{13}{12}\)

\(C=\frac{5.1.8.2.1.13}{15.14.27.5.12.12}\)

\(C=\frac{5.2.4.2.13}{3.5.14.27.5.4.3.2.2.3}\)

\(C=\frac{13}{3.14.27.5.3.3}\)

\(C=\frac{13}{51030}\)

đáp án là 0 nha em

\(C=\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)x\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)

\(\Rightarrow C=\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)x\left(\frac{1}{12}-\frac{1}{12}\right)\)

\(\Rightarrow C=\left(\frac{67}{11}+\frac{2}{33}-\frac{15}{117}\right)x0\)

\(\Rightarrow C=0\)

C=(67/111 +2/33 −15/117 )x(1/3 −1/4 −1/12 )

= 1/3 - 1/4 - 1/12 = 0

mà bao nhiêu nhân 0 vẫn bằng 0

vậy C = 0

ý là you là học sinh giỏi chứ j
 

Nó thì cô giải cho rồi, nó biết là phải

bài này dễ mà nhóm 3/429 ra có rồi khử liên tiếp

(1-1/3).(1-1/5).(1-1/7).(1-1/9).(1-1/11).(1-1/13).(1-1/2).(1-1/4).(1-1/6).(1-1/8).(1-1/10)

=2/3.4/5.6/7.8/9.10/11.12/13.1/2.3/4.5/6.7/8.9/10

=8/15.48/63.120/143.3/8.35/48.9/10

=384/945.360/1144.315/480

=138240/1081080.315/480

=43545600/518918400=84/1001

khó quá

\(\left(1-\frac{1}{3}\right)\left(1-\frac{1}{5}\right)\left(1-\frac{1}{7}\right)\)    \(\left(1-\frac{1}{11}\right)\)\(\left(1-\frac{1}{13}\right)\left(1-\frac{1}{2}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{6}\right)\)
 \(=1.\left(\frac{1}{3}-\frac{1}{2}\right).\left(\frac{1}{5}-\frac{1}{4}\right).\left(\frac{1}{7}-\frac{1}{6}\right)\)\(.\left(\frac{1}{11}-\frac{1}{10}\right).\frac{1}{13}\)
  \(=1.1.1.1.1.\frac{1}{13}\)
   \(=\frac{1}{13}\)
Cái này là chỉ do mình nghĩ thôi, ko biết đúng ko nữa
Có sai cko mình sorry nha!
Tk và kb hộ mình  với! thanks