Question 831320
Already been asked a few minutes ago.  I would start like this translation to symbols.


{{{p^2-(522+3p)=126}}}

Simplify.
{{{p^2-522-3p=126}}}
{{{p^2-3p-522-126=0}}}
{{{p^2-3p-648=0}}}


Examine the constant term.
648=9*72=9*2*36=9*2*6*6=3*3*2*2*2*3*3=2*2*2*3*3*3*3;
Consider 24 and 27 found from the prime factorization. 
Try:
{{{highlight((p  +24)(p -27)=0)}}} Factorable that way.
Pick {{{highlight(p=27)}}}