C1:3/7 x 9/26 - 1/14 x 1/13 - 1/7
=27/182 - 1/182 -1/7
=26/182 - 1/7
=0
mình cần cả lời giải xin lỗi mấy bạn ra kq 0 nhak
\(\frac{3}{7}.\frac{9}{26}-\frac{1}{14}.\frac{1}{13}-\frac{1}{7}\)
=\(\left\{\frac{3}{7}-\frac{1}{7}\right\}.\left\{\frac{9}{26}-\frac{1}{13}\right\}.\frac{1}{14}\)
=\(\left\{\frac{3}{7}+\frac{-1}{7}\right\}.\left\{\frac{9}{26}+\frac{-2}{26}\right\}.\frac{1}{14}\)
= \(\frac{2}{7}.\frac{7}{26}.\frac{1}{14}\)
=\(\frac{2.7.1}{7.26.14}\)=\(\frac{1.1.1}{7.13.2}\)
=\(\frac{1}{182}\)
