Question

[Triều Nguyễn Quốc]

1.Tính nhanh

a.(1/9 : 8/27 ) : 16/48 : 8/21

b.19/23 + 1/9 x 36/23

c.(13/23 + 1313/2323 - 131313/232323 ) x ( 1/3 + 1/4 - 7/12 )

Answer 1

[đoraemon]

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

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