First, group and combine like terms on the left side of the equation:
#9p + 5 - p = -7#
#9p - p + 5 = -7#
#9p - 1p + 5 = -7#
#(9 - 1)p + 5 = -7#
#8p + 5 = -7#
Next, subtract #color(red)(5)# from each side of the equation to isolate the #p# term while keeping the equation balanced:
#8p + 5 - color(red)(5) = -7 - color(red)(5)#
#8p + 0 = -12#
#8p = -12#
Now, divide each side of the equation by #color(red)(8)# to solve for #p# while keeping the equation balanced:
#(8p)/color(red)(8) = -12/color(red)(8)#
#(color(red)(cancel(color(black)(8)))p)/cancel(color(red)(8)) = (4 xx -3)/color(red)(4 xx 2)#
#p = (color(red)(cancel(color(black)(4))) xx -3)/color(red)(color(black)(cancel(color(red)(4))) xx 2)#
#p = -3/2#