Question

pllllssss am nevoiieeeee acummmmm!!!!!! dau 30 ppp

Answer 1

$a)E(x) = \left( \frac{x - 2}{2} - \frac{x {}^{2} - 4 }{4x}\right ) : \frac{x - 2}{2} + \frac{1}{2} \\ \\ E(x) = \frac{2x(x - 2) - (x {}^{2} - 4) }{4x} \times \frac{2}{x - 2} + \frac{1}{2} \\ \\ E(x) = \frac{2x {}^{2} - 4x - x {}^{2} + 4}{2x} \times \frac{1}{x - 2} + \frac{1}{2} \\ \\ E(x) = \frac{x {}^{2} - 4x + 4}{2x} \times \frac{1}{x - 2} + \frac{1}{2} \\ \\ E(x) = \frac{(x - 2) {}^{2} }{2x} \times \frac{1}{x - 2} + \frac{1}{2} \\ \\ E(x) = \frac{x - 2}{2x} + \frac{1}{2} \\ \\ E(x) = \frac{x - 2 + x}{2x} \\ \\ E(x) = \frac{2(x - 1)}{2x} \\ \\ E(x) = \frac{x - 1}{x} \\ \\\boxed{ E(x) = 1 - \frac{1}{x}} \\ \\ \\ \\ b) \frac{1}{x} \in\mathbb{Z}\implies x\in\text{D}_{1}\implies \boxed{x\in\{1, - 1\}}$