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1986 AIME Problems/Problem 1

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Problem

What is the sum of the solutions to the equation \displaystyle \sqrt[4]{x} = \frac{12}{7 - \sqrt[4]{x}}?

Solution

Let y = \sqrt[4]{x}. Then we have y(7 - y) = 12, or, by simplifying, y^2 - 7y + 12 = (y - 3)(y - 4) = 0.

This means that \sqrt[4]{x} = y = 3 or 4.

Thus the sum of the possible solutions for x is 4^4 + 3^4 = 337.

See also

1986 AIME (ProblemsResources)
Preceded by
First Question
Followed by
Problem 2
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