The point-slope form:

- slope
- point
We have the point
and the slope 
Substitute:

The exact value for the equation is true but I don't really think that's the question so anyways...
- 15.) The exact form for this equation is -13pi/3 and the decimal form -13.613...
- 16.) The exact form for this equation is 23pi/4 and the decimal form 18/064...
- 17.) The exact form is -7pi/2 as the decimal is -10.995...
- 18.) The exact is -29pi/6 and the decimal is -15.184...
volume of prism =area of Base ×height
It is neither one. Division by zero is undefined in math, so if the slope ends up being 5/0, the line has undefined slope.