a)\(\left(\dfrac{1}{9}:\dfrac{8}{27}\right):\left(\dfrac{16}{48}:\dfrac{8}{21}\right)\)
=\(\dfrac{3}{8}:\dfrac{7}{8}\)
=\(\dfrac{3}{7}\)
b)\(\dfrac{19}{23}+\dfrac{1}{9}\cdot\dfrac{36}{23}\)
=\(\dfrac{19}{23}+\left(\dfrac{1}{9}\cdot\dfrac{36}{23}\right)\)
=\(\dfrac{19}{23}+\left(\dfrac{1}{1}\cdot\dfrac{4}{23}\right)\)
=\(\dfrac{19}{23}+\dfrac{4}{23}\)
=\(\dfrac{23}{23}=1\)
c)\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot\left(\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{7}{12}\right)\)
=\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot\left(\dfrac{4}{12}+\dfrac{3}{12}-\dfrac{7}{12}\right)\)
=\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot0\)
=0
chúc bn học tốt!
