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2 years ago

Destiny reached the 3-km mark of the race at 10:36am and the 5-km mark at 10:44am. WHat is her running rate

Mathematics

1 answer:

andrew11 [14]2 years ago

7 0

Answer:

Running rate of Destiny is 15 kmph

Step-by-step explanation:

Running rate of Destiny is the speed at which Destiny is running.

It can be calculated by finding the difference in the distance covered to the difference in the time taken.

So,

Running rate = Difference in distance covered / Difference in time taken

Difference in distance covered = 5-3 = 2 km

Difference in time taken = 10:44 am - 10:36 am = 44 -36 minutes = 8 mins =8/60 hour = 2/15 hour

Running rate = 2/(2/15) kmph =(2*15)/2 = 15 kmph

∴Running rate of Destiny is 15 kmph

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x=2 is only solution while x=1 is extraneous solution

Option C is correct.

Step-by-step explanation:

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Solving:

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Now, factoring the term:

$x^2-2x-x+2=0\\x(x-2)-1(x-2)=0\\(x-1)(x-2)=0\\x-1=0\,\,and\,\, x-2=0\\x=1\,\,and\,\, x=2$

The values of x are x=1 and x=2

Checking for extraneous roots:

Extraneous roots: The root that is the solution of the equation but when we put it in the equation the answer turns out not to be right.

If we put x=1 in the equation, $\frac{1}{x-1}+\frac{2}{x}=\frac{x}{x-1}$ the denominator becomes zero i.e

$\frac{1}{1-1}+\frac{2}{1}=\frac{1}{1-1}\\\frac{1}{0}+2=\frac{1}{0}$

which is not correct as in fraction anything divided by zero is undefined. So, x=1 is an extraneous solution.

If we put x=2 in the equation,

$\frac{1}{x-1}+\frac{2}{x}=\frac{x}{x-1}$

$\frac{1}{2-1}+\frac{2}{2}=\frac{2}{2-1}\\\frac{1}{1}+1=\frac{2}{1}\\1+1=2\\2=2$

So, x=2 is only solution while x=1 is extraneous solution

Option C is correct.

Keywords: Solving Equations and checking extraneous solution

Learn more about Solving Equations and checking extraneous solution at:

#learnwithBrainly

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2 years ago

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The answer is C) 14 years.
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2 years ago

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2 years ago

The guttering hold up to 20 litre of rain water. Work out the length of guttering in meters if the diameter is 11.5cm.

bazaltina [42]

Answer:

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Step-by-step explanation:

Assuming this gutter is half a cylinder,

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It would be easier to convert the liters to m³ then to cm³ rather than converting directly. So,

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