Help please Find if Mia’s solution was correct, or if she made a mistake and in what step.

The equation Mia solved is,
[tex]\text{0}.1t-3=5[/tex]Soving stepwisely,
Step 1: By collecting like terms,
[tex]\begin{gathered} 0.1t=5+3 \\ 0.1t=8 \end{gathered}[/tex]Mia's solution is incorrect and her mistake was in the first step.