Your equation

is in the form
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The vertex only relies on "a" and "b" though, so that +9 doesn't really matter in this case. The vertex of a parabola is located where

So your x-coordinate is -1. You need to find f(-1) to find your y-coordinate, and then you list it in the form (-1, y).
Answer:
A
Step-by-step explanation:
The velocity of a moving body is given by the equation:

Is the velocity is <em>positive </em>(v>0), then our object will be moving <em>forwards</em>.
And if the velocity is negative (v<0), then our object will be moving <em>backwards</em>.
We want to find between which interval(s) is the object moving backwards. Hence, the second condition. Therefore:

By substitution:

Solve. To do so, we can first solve for <em>t</em> and then test values. By factoring:

Zero Product Property:

Now, by testing values for t<1, 1<t<4, and t>4, we see that:

So, the (only) interval for which <em>v</em> is <0 is the second interval: 1<t<4.
Hence, our answer is A.
Since x=8y, subsitute 8y for x in other equation
y=6x-11
y=6(8y)-11
y=48y-11
minus y both sides
0=47y-11
add 11 to both sides
11=47y
divide both sides by 47

subsitute taht for y to find x
x=8y




in (x,y) form
(x,y)
Can you please attach a photo or put up answer choices? It would help a lot. Thanks.
I am presuming that the question is who won or by how much did the winner win.
distance equals rate times time, or d = r*t
For the Hare d = 1600 and r = 10
1600 = 10 t
Divide both sides by 10
t = 160
The hare finished in 160 seconds
For the tortoise d = 1600 - 780 = 820 (due to the head start) and r = 5.3
820= 5.3 t
Divide both sides by 5.3
t = 154.72 (rounded to the hundredths place)
The tortoise won by 5. 28 seconds (160-154.72)