Tính hợp lí:
a) \(\frac{-8}{15}.\left(-30\right).\left(\frac{15}{-8}\right).\frac{9}{10}\)
b) \(2\frac{1}{18}.\frac{23}{24}.\frac{9}{37}.\frac{48}{-15}\)
c) A=\(\frac{-0,8+\frac{4}{7}+\frac{4}{9}}{0,3.\frac{3}{14}-\frac{3}{18}}+\frac{0,23-3,5+\frac{2}{7}}{0,69-10,5+\frac{6}{7}}\)
\(a,\frac{-8}{15}.\left(-30\right).\frac{15}{-8}.\frac{9}{10}\)
\(=-\left(\frac{8}{15}.\frac{15}{8}\right).\left(30.\frac{9}{10}\right)\)
\(=-1.27 =-27\)
\(b,2\frac{1}{18}.\frac{23}{24}.\frac{9}{37}.\frac{48}{-15}\)
\(=\frac{-37.23.9.48}{18.24.37.15}=\frac{23}{15}\)
c, chịu rồi
cảm ơn bạn nhé Ghost River