The factored version of the equation is (a-5) (a+4)
To the rest of the questions you should add an image to help visualize what you are asking us.
hope this helps !
Answer:

Step-by-step explanation:
Equation of a circle is given as :

Take the derivative of the above with respect to x

The equation of the tangent is given by :

Answer:
Slope 4
X-intercept -2
Y-intercept 8
Step-by-step explanation: