Answer :
[tex]\begin{gathered} 3x+5-13x=25 \\ 5-10x=25 \\ \text{Multiply both sides by -1:} \\ 10x-5=-25 \\ \text{add 5 to both sides:} \\ 10x=-20 \\ \text{divide both sides by 10:} \\ x=-\frac{20}{10} \\ x=-2 \end{gathered}[/tex]