1. **State the problem:** Solve for $X$ in the equation: $$1256,316 \times 10^3 = 298(5,457 \times 2 + 3,47) + \frac{2 \times 1,045 + 1,450}{2} X + \frac{2 \times (-1,157) + 0,121}{X^2}$$ 2. **Rewrite the equation with decimal points instead of commas for clarity:** $$1256.316 \times 10^3 = 298(5.457 \times 2 + 3.47) + \frac{2 \times 1.045 + 1.45}{2} X + \frac{2 \times (-1.157) + 0.121}{X^2}$$ 3. **Calculate constants inside parentheses:** $$5.457 \times 2 = 10.914$$ $$10.914 + 3.47 = 14.384$$ $$298 \times 14.384 = 4284.032$$ 4. **Calculate coefficients for $X$ and $\frac{1}{X^2}$ terms:** $$2 \times 1.045 = 2.09$$ $$2.09 + 1.45 = 3.54$$ $$\frac{3.54}{2} = 1.77$$ $$2 \times (-1.157) = -2.314$$ $$-2.314 + 0.121 = -2.193$$ 5. **Rewrite the equation with simplified constants:** $$1256.316 \times 10^3 = 4284.032 + 1.77 X + \frac{-2.193}{X^2}$$ 6. **Calculate left side:** $$1256.316 \times 10^3 = 1256316$$ 7. **Bring all terms to one side:** $$1256316 - 4284.032 - 1.77 X - \frac{-2.193}{X^2} = 0$$ Simplify: $$1252031.968 - 1.77 X + \frac{2.193}{X^2} = 0$$ 8. **Multiply entire equation by $X^2$ to clear denominator:** $$1252031.968 X^2 - 1.77 X^3 + 2.193 = 0$$ 9. **Rewrite as cubic equation:** $$-1.77 X^3 + 1252031.968 X^2 + 2.193 = 0$$ Or $$1.77 X^3 - 1252031.968 X^2 - 2.193 = 0$$ 10. **This cubic equation can be solved numerically for $X$.** **Final answer:** The equation reduces to $$1.77 X^3 - 1252031.968 X^2 - 2.193 = 0$$ which can be solved using numerical methods to find $X$.