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.
It's C. In order to be in standard form you have to have all your exponents in descending order. They don't all have to be there in order, the ones that are just have to go from highest to lowest.