Find all real solutions to the equation: \( 2 x^{3}-25=-x^{2}+50 x \) \( x=\square \)
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First, let's rearrange the equation into a standard form. We have: \[ 2x^3 + x^2 - 50x - 25 = 0. \] Now, to find the real solutions, we can apply the Rational Root Theorem. This suggests checking factors of \(-25\) (the constant term) over factors of \(2\) (the leading coefficient). Possible rational roots include \( \pm 1, \pm 5, \pm 25\) and so forth. Testing \(x = 5\): \[ 2(5)^3 + (5)^2 - 50(5) - 25 = 2(125) + 25 - 250 - 25 = 250 + 25 - 250 - 25 = 0. \] So, \(x = 5\) is a root. We can use synthetic division to factor the polynomial by \(x - 5\): ``` 5 | 2 0 1 -50 -25 | 10 50 255 ------------------------ 2 10 51 205 ``` This gives us the quotient \(2x^2 + 10x + 51\). The full factorization is: \[ 2x^3 + x^2 - 50x - 25 = (x - 5)(2x^2 + 10x + 51). \] Next, we need to find the roots of \(2x^2 + 10x + 51 = 0\) using the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\): \[ x = \frac{-10 \pm \sqrt{10^2 - 4 \cdot 2 \cdot 51}}{2 \cdot 2} = \frac{-10 \pm \sqrt{100 - 408}}{4} = \frac{-10 \pm \sqrt{-308}}{4}. \] Since the discriminant is negative (\(-308\)), this quadratic has no real solutions. Thus, the only real solution to the original equation is: \[ x = 5. \] Therefore, the final answer is: \( x = 5 \)