Question

Упросите выражение
(4x-y)/(2x+x^0.5*y^0.5) и найти значение при х=324 у=81

Answer 1

$frac{4x-y}{2x+sqrt{x}sqrt{y}} =frac{(2sqrt{x}-sqrt{y})(2sqrt{x}+sqrt{y})}{sqrt{x}(2sqrt{x}+sqrt{y})} =frac{2sqrt{x}-sqrt{y}}{sqrt{x}} =2-frac{sqrt{y}}{sqrt{x}} \ \ x=324 \ sqrt{x} =18 \ y=81 \ sqrt{y} =9 \ \ 2-frac{sqrt{81}}{sqrt{324}}=2-frac{9}{18}=2- frac{1}{2} = frac{3}{2} =1,5$