1/2(-p+23+-p+15)=6p-23

1/2(-p+23+-p+15)=6p-23

 You mean this, right?:

(1/2)[-p + 23 + (-p) + 15] = 6p - 23     calculate: -p - p, and 23 + 15:

(1/2)(38 - 2p) = 6p - 23                 Find the product on left side:

19 - p  = 6p - 23                      Add p + 23 on both sides:

42 = 7p                      Divide both sides by 7

p = 6

I am very impressed by the quality of your answers Tetration.

Thank you.  You are a great asset to this forum.   

*** Thx :) ***