Nikita ran a 5-kilometer race in 39 minutes (0.65 of an hour) without training beforehand. in the first part of the race, her average speed was 8.75 kilometers per hour. for the second part of the race, she started to get tired, so her average speed dropped to 6 kilometers per hour. which expression represents nikita’s distance for the second part of the race?

6t
0.65 – t
6(0.65) – t
6(0.65 – t)

The answer is 6(0.65-t)

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

a

b

d

step-by-step explanation: