i forgot how to do this. please give me a example on how i do this thank u

Answer:
[tex]t \in \mathrm {R}[/tex]
Step-by-step explanation:
[tex]2t + 6 = 2(t + 3)[/tex]
[tex]2t + 6 = 2t + 6[/tex]
[tex]2t + 6 - 2t = 2t - 6 - 2t[/tex]
[tex]6 = 6[/tex]
[tex]t \in \mathrm {R}[/tex]