Answer
a) The solution to this equation would be $ p= -10 $.
b) A good starting point would be using $0$ and $-5$.
Work Step by Step
a) As seen from the table, slowly changing the p value will give a good indication on the direction that should be taken in terms of the value to use. In this case, the number should be negative because a positive number would result in a number less than what we require.
b) Using these two numbers will give a good indication on the value that is required. Zero allows for the direction to be decided (whether p should be negative or positive) and -5 will show how extreme the changes are, which will allow for smaller adjustments to be made in order to get the end value of 55.
