( can a/ 2 tru 1/ 2 can a ) nhan voi a tru can a / can a +1 tru a + can a / can a -1. Rut gon, giai chi tiet co dieu kien xac dinh

Đáp án:

Giải thích các bước giải: \[\begin{array}{l} \left( {\frac{{\sqrt a }}{2} - \frac{1}{{2\sqrt a }}} \right)\left( {\frac{{a - \sqrt a }}{{\sqrt a + 1}} - \frac{{a + \sqrt a }}{{\sqrt a - 1}}} \right)\,\,\,\,\,\left( {DK:a > 0;a \ne 1} \right)\\ = \frac{{a - 1}}{{2\sqrt a }} \cdot \left( {\frac{{\sqrt a {{\left( {\sqrt a - 1} \right)}^2} - \sqrt a {{\left( {\sqrt a + 1} \right)}^2}}}{{\left( {\sqrt a + 1} \right)\left( {\sqrt a - 1} \right)}}} \right)\\ = \frac{{a - 1}}{{2\sqrt a }} \cdot \frac{{\sqrt a \cdot \left( {a - 2\sqrt a + 1 - a - 2\sqrt a - 1} \right)}}{{a - 1}}\\ = \frac{{ - 4\sqrt a }}{2} = - 2\sqrt a \end{array}\]