How do you write \[2{\rm{ }}1/4\] an improper fraction?

Hint:
In the given question, we have been asked to represent the given fraction as an improper fraction. For doing that, first we multiply the denominator with the separate number and then add the numerator to it. This is going to give us the improper fraction equivalent of the given mixed fraction.

Complete Step by Step Solution:
Consider a mixed fraction of the type \[a\dfrac{b}{c}\], where \[a,b,c \in N\] and \[c > b\].
Then the improper fraction equivalent of this mixed fraction is written as:
\[\dfrac{{a \times c + b}}{c}\]
Hence, applying the same formula to \[2{\rm{ }}1/4\], we get the improper fraction as

\[\dfrac{{2 \times 4 + 1}}{4} = \dfrac{9}{4}\]

Note:
The mixed fractions are represented in two ways in which both are equal: \[a\dfrac{b}{c}\] or \[a + \dfrac{b}{c}\]. Both of these mean the same thing, just a little different way to show it.