Question

có ai giúp mình được không :

a) \(\dfrac{1}{4}-\dfrac{3}{4}:\left(\dfrac{-5}{8}\right)\)

b) \(3-\left(\dfrac{-6}{7}\right)^0+\sqrt{\dfrac{1}{16}}:2\)

c) \(\dfrac{9^5\cdot2^6}{4^3\cdot3^8}\)

Answer 1

\(a)\dfrac{1}{4}-\dfrac{3}{4}:\left(\dfrac{-5}{8}\right)\)

\(=\dfrac{1}{4}-\dfrac{3}{4}.\dfrac{-8}{5}\)

\(=\dfrac{1}{4}-\dfrac{-6}{5}\)

\(=\dfrac{5}{20}+\dfrac{24}{20}\)

\(=\dfrac{29}{20}\)

\(b)3-\left(\dfrac{-6}{7}\right)^0+\sqrt{\dfrac{1}{16}}:2\)

\(=3-1+\sqrt{\left(\dfrac{1}{4}\right)^2}:2\)

\(=2+\dfrac{1}{4}.\dfrac{1}{2}\)

\(=\dfrac{16}{8}+\dfrac{1}{8}\)

\(=\dfrac{17}{8}\)

\(c)\dfrac{9^5.2^6}{4^3.3^8}=\dfrac{\left(3^2\right)^5.2^6}{\left(2^2\right)^3.3^8}=\dfrac{3^{10}.2^6}{2^6.3^8}=3^2=9\)