Question

$15 + \frac{1}{2} p = 3p$

Answer 1

15+p/2 =3p => multiply the following quantity by 2=>
30+p=6p=> 30=6p-p =5p => p=30/5 =6.

Answer 2

15 + p/2 =3 p
15 =3 p -p/2
=( 6p -p) /2
30 =5p
p =6