25x^2 - 16 = (5x - 4)(5x + 4)
For 80 guests you will need 80/10 = 8 times more than for 10 guests:
8*9.50 = $76
Refreshment for 80 guests costs $76.
The answer would be C. Mike can drive at the most 500 miles.
$200 - the rent for the week ($125)= $75
$75/($.15) the money per mile
500 miles.
Hope This Helps!
~Cupkake
The vertex form:

(h,k) - the coordinates of the vertex

The coordinates of the vertex are
(-4,13).