6p-x-5p+7x ( you can only add/subtract like terms meaning something with a p cannot be added/subtracted with something with an x, p with p and x with x only)
rewrite this equation to make it easier
6p-5p-x+7x ( this is the same equation only rewritten to put the like terms together)
(6-5)=1
1p-x+7x (-1+7= 6)
p+6x is your final answer.