[tex]\begin{gathered} \text{The two books that weigh the most are, } \\ 2\frac{2}{4}=\frac{10}{4},\text{ and }1\frac{3}{4}=\frac{7}{4} \\ So,\text{ the difference between theese books is, } \\ \Rightarrow\frac{10}{4}-\frac{7}{4} \\ \Rightarrow\frac{10-7}{4} \\ \Rightarrow\frac{3}{4}\text{ pounds.} \end{gathered}[/tex]
