Tính a) -6 . (-2/3) . 0,25 b) -15/4 . (-7/15) . ( -2 2/5)

* Hướng dẫn giải

a) $-6.\left(-\frac{2}{3}\right).0,25=4.\frac{1}{4}=1$

b) $-\frac{15}{4}.\left(\frac{-7}{15}\right).\left(-2\frac{2}{5}\right)=\frac{7}{4}.\left(-\frac{12}{5}\right)=-\frac{21}{5}$