The answer is -4,7
The denominator can't equal zero. Factor the denominator:
x^2 - 3x - 28=
(X - 7)(x + 4); next set each set of parentheses equal to 0;
x - 7 = 0; so x=7 is one value
x + 4 = 0; so x=-4 is the other
Remember, x = 7 and x= -4 make the denominator zero, which is a "restriction" because you can't divide by zero.
Answer:
E[T] = 10
Step-by-step explanation:
A distribution is called uniform if each outcome has the same probability of happening.
The uniform distribution has two bounds, a and b, and the expected value of the uniform distribution is given by:

Uniformly distributed between 0 and 20 minutes.
This means that 
Let T be the number of minutes you wait until you board a bus. Find E[T].
This is
![E[T] = \frac{a + b}{2} = \frac{0 + 20}{2} = 10](https://tex.z-dn.net/?f=E%5BT%5D%20%3D%20%5Cfrac%7Ba%20%2B%20b%7D%7B2%7D%20%3D%20%5Cfrac%7B0%20%2B%2020%7D%7B2%7D%20%3D%2010)
E[T] = 10
The answer should probably be 2627.1 feet
Hope this helps!