Arrange the following numbers in descending order:

$5\dfrac{3}{4}$, 5.721, $5\dfrac{7}{8}$, $5\dfrac{17}{25}$, 5.693

First, convert each mixed fraction into a decimal number.

$5\dfrac{3}{4} = 5 + \dfrac{3}{4} = 5 + \dfrac{3 \times 25}{4 \times 25} = 5 + \dfrac{75}{100} = 5 + 0.75 = 5.75$

$5\dfrac{7}{8} = 5 + \dfrac{7}{8} = 5 + \dfrac{7 \times 125}{8 \times 125} = 5 + \dfrac{875}{1000} = 5 + 0.875 = 5.875$

$5\dfrac{17}{25} = 5 + \dfrac{17}{25} = 5 + \dfrac{17 \times 4}{25 \times 4} = 5 + \dfrac{68}{100} = 5 + 0.68 = 5.68$

So the given numbers in decimal form are:

5.75, 5.721, 5.875, 5.68, 5.693

Converting into like decimals, each having three decimal places:

5.750, 5.721, 5.875, 5.680, 5.693

Clearly, 5.875 > 5.750 > 5.721 > 5.693 > 5.680.

Hence, the given numbers in descending order are:

$5\dfrac{7}{8}$ > $5\dfrac{3}{4}$ > 5.721 > 5.693 > $5\dfrac{17}{25}$