Answer:
The rocket will take 4.5 seconds to reach its maximum height.
Step-by-step explanation:
The height of a missile t seconds after it has been fired is given by h=-4.9*t²+44.1*t
This function is a quadratic function of the form f (x) = a*x² + b*x + c. In this case a=-4.9, b=44.1 and c=0
To calculate how many seconds it will take for the rocket to reach its maximum height, I must calculate the maximum of the function. The maximum of a quadratic function is the vertex of the parabola. The x coordinate of the vertex will be simply: 
. The y coordinate of the vertex corresponds to the function evaluated at that point.
In this case the x coordinate of the vertex corresponds to the t coordinate. In other words, by calculating the x coordinate of the vertex, you are calculating the maximum time t it will take for the rocket to reach its maximum height. So:
t=4.5
<u><em>The rocket will take 4.5 seconds to reach its maximum height.</em></u>
14 divided by 1/3= 42 so 42 plates. Hope it helps! P.S. Can you mark me brainliest if I'm right?
Answer:
Usually pounds (lb) .About an an average of 20 to 25 pounds (lbs)
Step-by-step explanation:
Since Marvin uses Customary units, and considering the Watermelon.
Pounds, He could estimate based on average of 20 to 25 pounds.
He could choose another customary units, but it wouldn't be practical and unusual to say a watermelon of 160 quarters, also it would leave all the listeners without parameters.
So, definitely pounds.
Rational ! the number doesn't repeat forever or anything like that. it simplifies nicely.
Answer: Choice B
(-2, 5)
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Explanation:
The original system is
Multiply both sides of the second equation by 3. Doing so leads to this updated system of equations
Now add straight down
The x terms add to -4x+3x = -1x = -x
The y terms add to 3y+(-3y) = 0y = 0
The terms on the right hand sides add to 23+(-21) = 2
We end up with the equation -x = 2 which solves to x = -2
Now use this to find y. You can pick any equation with x,y in it
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-4x+3y = 23
-4(-2)+3y = 23
8+3y = 23
3y = 23-8
3y = 15
y = 15/3
y = 5
Or
x-y = -7
-2-y = -7
-y = -7+2
y = -5
y = 5
Either way, we get the same y value.
So that's why the solution is (x,y) = (-2, 5)
