We must use the distributive property for the middle part.
After we do that, the equation can be displayed as 2p + 4 + 5p - 5 + p + 7
Combine like terms
8p + 4 - 5 + 7
Add 4 and 7
8p + 11 - 5
Subtract 5
8p + 6
The simplified version of 2p + 4 + 5(p - 1) + p + 7 = 8p + 6