\(C=\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)x\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)
\(\Rightarrow C=\left(\frac{67}{111}+\frac{2}{33}-\frac{15}{117}\right)x\left(\frac{1}{12}-\frac{1}{12}\right)\)
\(\Rightarrow C=\left(\frac{67}{11}+\frac{2}{33}-\frac{15}{117}\right)x0\)
\(\Rightarrow C=0\)
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