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Encuentra dos numeros positivos tal que su cuadrado menos su quintuplo sea 36

User Confusion
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1 Answer

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The two positive numbers are:
\[ (x, y) = \left((5 + √(221))/(2), (7 + √(221))/(2)\right) \]

Let's denote the two positive numbers as
\(x\) and
\(y\). The problem states that their square minus their fivefold is equal to 36. We can express this algebraically:


\[ x^2 - 5y = 36 \]

Now, we need another relationship between
\(x\) and
\(y\). Since the problem doesn't provide one explicitly, let's assume another relationship that might make the problem solvable. For example, we can assume that the two numbers are consecutive. Therefore:


\[ y = x + 1 \]

Now, we can substitute
\(y = x + 1\) into the first equation:


\[ x^2 - 5(x + 1) = 36 \]

Now, solve this equation to find the values of
\(x\) and
\(y\):


\[ x^2 - 5x - 41 = 0 \]

Using the quadratic formula:


\[ x = (-b \pm √(b^2 - 4ac))/(2a) \]

For the equation
\(x^2 - 5x - 41 = 0\),
\(a = 1\),
\(b = -5\), and
\(c = -41\). Plugging these values into the quadratic formula:


\[ x = (5 \pm √(5^2 - 4(1)(-41)))/(2(1)) \]


\[ x = (5 \pm √(221))/(2) \]

The square root of 221 is an irrational number, so there are two solutions for
\(x\), one using the positive square root and one using the negative square root.

The two positive numbers are:


\[ (x, y) = \left((5 + √(221))/(2), (7 + √(221))/(2)\right) \]

And the other solution using the negative square root:


\[ (x, y) = \left((5 - √(221))/(2), (7 - √(221))/(2)\right) \]

Both solutions satisfy the conditions given in the problem.

User Takahiko Kawasaki
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