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jmc

algebra senior

Problem

The real root of the equation can be written in the form , where , , and are positive integers. Find .
Solution
In general, the solutions to cubic equations are very messy, so we hope there is a trick to solving this particular equation.

Noticing the pattern of coefficients, which appears in the expansion we rewrite the left-hand side as or Thus, , and since is real, To rationalize the denominator, we write by the difference of cubes factorization. The answer is .
Final answer
98