Giải thích các bước giải:
a) $\frac{-9}{34}×\frac{17}{4}=\frac{-153}{136}=\frac{-9}{8}$
b) $\frac{-20}{41}×\frac{-4}{5}=\frac{80}{205}=\frac{16}{41}$
c) $\frac{-6}{7}×\frac{21}{2}=\frac{-126}{14}=-9$
d) $(\frac{-4}{17})×(-6\frac{3}{8})=(\frac{-4}{17})×(\frac{-45}{8})=\frac{180}{136}=\frac{45}{34}$
e) $(-3,25)×(2\frac{10}{3})=(\frac{-13}{4})×(\frac{16}{3})=\frac{-208}{12}=\frac{-52}{3}$
f) $(-3,8)×(-2\frac{9}{28})=(\frac{-19}{5})×(\frac{-47}{28})=\frac{893}{140}$
g) $\frac{-8}{15}×1\frac{1}{4}=\frac{-8}{15}×\frac{5}{4}=\frac{-40}{60}=\frac{-2}{3}$
h) $2\frac{2}{5}×\frac{-3}{4}=\frac{12}{5}×\frac{-3}{4}=\frac{-36}{16}=\frac{-9}{4}$
i) $1\frac{1}{17}×(-2\frac{1}{8}=\frac{18}{17}×\frac{-17}{8}=\frac{-306}{136}=\frac{-9}{4}$
m)$\frac{17}{15}:\frac{4}{3}=\frac{17}{15}×\frac{3}{4}=\frac{51}{60}=\frac{17}{20}$
Học tốt!!!
