Convert to usual notation to solve the difference in an easier way.
[tex]\begin{gathered} 2.4\times10^{-1}=0.24 \\ 5.5\times10^{-2}=0.055 \end{gathered}[/tex][tex]0.24-0.055=0.185[/tex]Convert the answer to scientific notation:
[tex]0.185=1.85\times10^{-1}[/tex]