Answer:
t = 2
Step-by-step explanation:
Notice that this expression for the projectile's path is that of a quadratic function with negative leading term. The graph of it therefore consists of a parabola with the branches pointing down (due to he negative leading coefficient). Therefore, the maximum of such parabola will reside at its vertex.
Recall that the formula for the position of the vertex in a general parabolic function of the form:
, is given by the expression: 
In our case, the variable "x" is in fact "t", the leading coefficient (
) is -5, and the coefficient for the linear term (
) is 20.
Therefore, the maximum of the path will be when 
In customary units, the length of a car would be in feet.
(x-y)(x^2+xy+y^2)
The first parentheses contain the cubed root of both the terms so x and y respectively. second parentheses follows the formula (a^2 + ab + b^2)
x corresponds to a and y corresponds to b. The signs are what change depending on what the original equation is. Since the original is a subtraction then the signs are -/+/+. you can remember it using the acronym SOAP. (S = same, O = opposite, AP = always positive) So the first sign is x - y (same as subtraction from original), the second and third are x^2 + xy + y^2 (opposite is a plus, and the last sign is always a positive.
The answer is C.
Octagon is 135
And decagon is 144
So 144-135=11