Answer: 

When writing this on a keyboard, we could say p = -10+sqrt(3)
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Step-by-step explanation:
We're told the angle between the line and x axis is 

This is one of the infinitely many exact solutions to the equation 
 where 
 (Greek letter theta) is the angle in question.
It turns out that the tangent ratio is exactly the slope of a line.
- slope = rise/run
 - tan(angle) = opposite/adjacent
 
Both describe a ratio of how far something moves up or down, over how far it moves to the right.
So saying 
 means that the slope of our mystery line is exactly 

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What we'll do is compute the slope on the points 
 
That produces some algebraic expression in terms of p. That expression is set equal to the previously mentioned slope of 
 which will allow us to solve for p.
Part 1

Part 2
