The long way to do this is to plug each value from the list {1, 2, 3, 4, 5, 6, 7, 8, 9} into the inequality 4p-p < 13 to see which make the inequality true. Those values are then recorded for the final answer.
The shorter way is to use algebra to solve for p
4p-p < 13
3p < 13
3p/3 < 13/3
p < 4.333 which is approximate
Since we're dealing with whole numbers from the original list, we can round 4.333 up to the nearest whole number and we now have p < 5
So the solutions would be 1,2,3,4 as they all make 4p-p < 13 true
The values 5 and higher would make 4p-p too large
hope this helps!!!!