Rút gọn biểu thức T = ( 1 - 2 căn bậc hai b /a + b /a ) : a ^ 1/2 - b ^ 1/2

Ta có

\(\begin{array}{*{20}{l}}T&{ = \left( {1 - 2\sqrt {\frac{b}{a}}  + \frac{b}{a}} \right):{{\left( {{a^{\frac{1}{2}}} - {b^{\frac{1}{2}}}} \right)}^2} = {{\left( {1 - \sqrt {\frac{b}{a}} } \right)}^2}:{{(\sqrt a  - \sqrt b )}^2}}\\{}&{ = \frac{{{{(\sqrt a  - \sqrt b )}^2}}}{{{{(\sqrt a )}^2}}}\frac{1}{{{{(\sqrt a  - \sqrt b )}^2}}} = \frac{1}{a}}\end{array}\)