[tex]x + \frac{1}{x} = 11a \\ (x + \frac{1}{x} ) ^{2} = 11a ^{2} \\ x ^{2} + 2 \times x \times \frac{1}{x} + ( \frac{1}{x} ) ^{2} = 121a {}^{2} \\ x ^{2} + \frac{2x}{x} + \frac{1}{x {}^{2} } = 121a {}^{2} \\ x {}^{2} + 2 + \frac{1}{x {}^{2} } = 121a {}^{2} \\ x {}^{2} + \frac{1}{x {}^{2} } = 121a {}^{2} - 2[/tex]
Sper ca te-am putut ajuta :)
