Answer :

[tex]3t-7=5t\\ 2t=-7\\ 6t=-21[/tex]
[tex]3t-7=5t\\\\5t=3t-7\ \ \ \ /-3t\\\\5t-3t=3t-3t-7\\\\2t=-7\ \ \ \ /\cdot3\\\\2t\cdot3=-7\cdot3\\\\6t=-21[/tex]