Question

решите пожалуйста срочно надо!!!!

Answer 1

7)
$(frac{x-y}{x^2+yx}- frac{x}{y^2+xy}):( frac{1}{x+y} + frac{y^2}{x^3-xy^2})+ frac{x}{y} =1 \ \ 1) frac{x-y}{x^2+yx}- frac{x}{y^2+xy}= frac{xy-y^2-x^2}{xy(x+y)}=- frac{x^2-xy+y^2}{xy(x+y)} \ \ 2)frac{1}{x+y} + frac{y^2}{x^3-xy^2}= frac{x^2-xy+y^2}{x(x-y)(x+y)} \ \ 3) - frac{x^2-xy+y^2}{xy(x+y)} :frac{x^2-xy+y^2}{x(x-y)(x+y)}=- frac{x^2-xy+y^2}{xy(x+y)} * frac{x(x-y)(x+y)}{x^2-xy+y^2} =\ \ =- frac{x-y}{y}= frac{y-x}{y} \ \ 4)frac{y-x}{y}+ frac{x}{y} = frac{y-x+x}{y}=1$


9)

$(frac{x+y}{x-y}+ frac{x-y}{x+y}):(frac{x+y}{x-y}-frac{x-y}{x+y})* frac{x^2y^2}{(x-y)^2+(x+y)^2}= frac{xy}{4} \ \ 1)frac{x+y}{x-y}+ frac{x-y}{x+y}= frac{x^2+xy+xy+y^2+x^2-xy-xy+y^2}{(x-y)(x+y)}= frac{2(x^2+y^2)}{(x-y)(x+y)} \ \ 2)frac{x+y}{x-y}-frac{x-y}{x+y}= frac{x^2+xy+xy+y^2-x^2+xy+xy-y^2}{(x-y)(x+y)} = frac{4xy}{(x-y)(x+y)} \ \ 3)frac{2(x^2+y^2)}{(x-y)(x+y)} :frac{4xy}{(x-y)(x+y)}=frac{2(x^2+y^2)}{(x-y)(x+y)}* frac{(x-y)(x+y)}{4xy}= frac{x^2+y^2}{2xy}$

$4) frac{x^2+y^2}{2xy}* frac{x^2y^2}{(x-y)^2+(x+y)^2}=frac{x^2+y^2}{2xy}* frac{x^2y^2}{x^2-2xy+y^2+x^2+2xy+y^2}= \ \ = frac{x^2+y^2}{2xy}* frac{x^2y^2}{2(x^2+y^2)}= frac{xy}{4}$