Firstly, we are going add [tex]12[/tex] on each of the sides that we're working with. like ↓
[tex]p - 12 + 12 \\ \\ = -2 + 12 [/tex]
This gives us [tex] \frac{2}{3}p = 10 [/tex] (if you are wondering how we got the out come of [tex]10 [/tex] it is because I added [tex]-2 + 12 = 10 [/tex]
Now multiply [tex] \frac{3}{2} [/tex] on each of your sides