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Sergeu [11.5K]
3 years ago
9

Ming throws a stone off a bridge into a river below.

Mathematics
2 answers:
AURORKA [14]3 years ago
6 0

Answer:

1 seconds after being thrown, the stone reaches its max height

Step-by-step explanation:

The parabolic (quadratic) equation is:

h(x)=-5(x-1)^2+45

Lets expand this in the form ax^2+bx+c, so we have:

h(x)=-5(x-1)^2+45\\h(x)=-5(x^2-2x+1)+45\\h(x)=-5x^2+10x-5+45\\h(x)=-5x^2+10x+40

We can say the values of a,b, and c, now to be:

a = -5

b = 10

c = 40

The number of seconds at which the max would occur is given by the point, x, at:

x=-\frac{b}{2a}

We know a and b, let's find the seconds, x,

x=-\frac{b}{2a}=-\frac{10}{2(-5)}=-\frac{10}{-10}=--1=1

Hence,

1 seconds after being thrown, the stone reach its max height

kifflom [539]3 years ago
3 0

Answer:

1 second

Step-by-step explanation:

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ratelena [41]
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Solve the simultaneous equations:<br><br> 5x + 3y = 9<br> 7x - 2y = 25<br><br> x=__<br> y=__
kondor19780726 [428]

Answer:

x= 3, y= -2

Step-by-step explanation:

5x+3y= 9

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x= 3

5 0
3 years ago
In an experiment, every hour 20% of the total number of bacteria die, and those remaining bacteria
Ne4ueva [31]

Answer:

Hi there!

Your answer is;

There are 50 bacteria after 3 hours

Step-by-step explanation:

After three hours, with a rate of 20% an hour, 60% should have died

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7 0
4 years ago
A sample of 13 sheets of cardstock is randomly selected and the following thicknesses are measured in millimeters. Give a point
valina [46]
<h3>Answer:  0.061</h3>

===============================================

Explanation:

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Then divide over 13 (the number of values) to get 24.54/13 = 1.8876923 which is approximate.

So the mean is approximately 1.8876923

---------------------

Now make a spreadsheet as shown below

We have the first column as the x values, which are the original numbers your teacher provided. The second column is of the form (x-M)^2, where M is the mean we computed earlier. We subtract off the mean and square the result.

After we compute that column of (x-M)^2 values, we add them up to get what is shown in the highlighted yellow cell at the bottom of the column.

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sqrt(0.00366923077) = 0.06057417576822

This rounds to 0.061 which is the final answer.

5 0
3 years ago
What is Ten percent of a number added to that number?
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8 0
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