Question

tính

\(\dfrac{5^4.20^4}{25^4.4^5}\)

( -2)³.\(\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)

Answer 1

a)\(\dfrac{5^4.20^4}{25^4.4^5}\)

\(=\dfrac{5^4.\left(4.5\right)^4}{\left(5.5\right)^4.4^5}\)

\(=\dfrac{5^4.4^4.5^4}{5^4.5^4.4^5}\)

\(=\dfrac{4^4}{4^5}\)

\(=\dfrac{1}{4}\)

Answer 2

\(b)\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)

\(=\left(-8\right).\left(\dfrac{3}{4}-\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)\)

\(=\left(-8\right).\dfrac{1}{2}:\dfrac{13}{12}\)

\(=\left(-4\right):\dfrac{13}{12}=\dfrac{-48}{13}\)

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