Answer:
[tex]\huge\boxed{p=6}[/tex]
Step-by-step explanation:
[tex]\dfrac{p}{2}+15=18\qquad|\text{subtract 15 from both sides}\\\\\dfrac{p}{2}+15-15=18-15\\\\\dfrac{p}{2}=3\qquad|\text{multiply both sides by 2}\\\\2\!\!\!\!\diagup\cdot\dfrac{p}{2\!\!\!\!\diagup}=2\cdot3\\\\p=6[/tex]
