Question

VA ROG FOARTE FRUMOS!!!

Answer 1

$(x + \frac{1}{x} ) ^{2} = 81 \\ {x}^{2} + \frac{1}{ {x}^{2} } + 2 \times x \times \frac{1}{x} = 81 \\ {x}^{2} + \frac{1}{ {x}^{2} } + 2 = 81 \\ {x}^{2} + \frac{1}{ {x}^{2} } = 79$