các bạn làm ơn giúp mình với đc ko , mình đang cần gấp !!!!
Trả lời:
\(A=\frac{6}{8}.\frac{8}{13}+\frac{6}{13}.\frac{9}{7}-\frac{3}{13}.\frac{6}{7}\)
\(A=\frac{6}{13}+\frac{54}{91}-\frac{18}{91}\)
\(A=\frac{6}{7}\)
\(B=\left(\frac{5}{4}+\frac{3}{4}\right).\frac{4}{7}.\left(\frac{3}{4}+\frac{9}{4}\right).\frac{4}{7}\)
\(B=\frac{2}{1}.\frac{4}{7}.\frac{3}{1}.\frac{4}{7}\)
\(B=\frac{8}{7}.\frac{12}{7}\)
\(B=\frac{96}{49}\)
\(D=\left(\frac{1}{2}+\frac{3}{4}-\frac{5}{6}\right).\frac{24}{5}\)
\(D=\left(\frac{6}{12}+\frac{9}{12}-\frac{10}{12}\right).\frac{24}{5}\)
\(D=\frac{5}{12}.\frac{24}{5}\)
\(D=\frac{2}{1}=2\)
\(C=-\frac{5}{7}.\frac{1}{35}+\frac{6}{49}.\left(-\frac{8}{1}\right)+\frac{16}{-3}.\frac{-3}{8}.\)
\(C=-\frac{1}{49}+\left(-\frac{48}{49}\right)+2\)
\(C=-1+2\)
\(C=1\)
