Verified Answer :

Answer

Find out the  solution to the system of equations .

To prove

As the equations are

y = x – 10 , 4 = 2xy

\(Put\ y = \frac{4}{2x}\)

in  the equation  y = x – 10

\(\frac{4}{2x} = x - 10\)

Than the equation becomes

2x² - 20x - 4 = 0

Taking 2 as common

x² - 10x - 2 = 0

Now using the discriment formula

\(D = -b\pm \frac{\sqrt{b^{2} - 4ac}}{2a}\)

Here a = 1 , b = -10 , c = -2

Put in the above

\(x = 10\pm \frac{\sqrt{(-10)^{2} - 4\times 1\times -2}}{2}\)

\(x = 10\pm \frac{\sqrt{100+ 8}}{2}\)

\(x = 5\pm \frac{\sqrt{108}}{2}\)

\(x = 5\pm \frac{6\sqrt{3}}{2}\)

\(x = 5\pm 3\sqrt{3}\)

Thus the solution are

\(x = 5\ + 3\sqrt{3}\)

Put in the  4 = 2xy

\(y = \frac{4}{2(5+3\sqrt{3} )}\)

\(y = \frac{2}{(5+3\sqrt{3} )}\)

When

\(x = 5\ - 3\sqrt{3}\)

Put in the  4 = 2xy

\(y = \frac{4}{2(5 -3\sqrt{3} )}\)

\(y = \frac{2}{(5 - 3\sqrt{3} )}\)



 

Answer:

C is the answer

Step-by-step explanation:

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