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Решите задачу:

$\frac{x}{y^2}+ \frac{2}{y}= \frac{x+2y}{y^2} \\\ \frac{2x}{y} - \frac{x}{y^2}= \frac{2xy-x}{y^2} \\\ 1- \frac{a}{a^2}+ \frac{1}{a}= 1- \frac{1}{a}+ \frac{1}{a}=1 \\\ x+ \frac{a}{x^2} +x- \frac{a}{ax}=2x+ \frac{a}{x^2} - \frac{x}{x^2}=\frac{2x^3+a-x}{x^2} \\\ y+ \frac{b}{y^2} +y+ \frac{b}{by} =2y+ \frac{b}{y^2} + \frac{y}{y^2} = \frac{2y^3b+y}{y^2}$
$a- \frac{2b}{ab^2}-b- \frac{2a}{a^2b}=a-b- \frac{2}{ab}- \frac{2}{ab}= \frac{a^2b-ab^2-4}{ab} \\\ c- \frac{d}{c^2d}-c+ \frac{d}{cd^2}= \frac{1}{cd}- \frac{1}{c^2}= \frac{c-d}{c^2d} \\\ a^2- \frac{b^2}{b^5} + \frac{2}{b^3}=a^2- \frac{1}{b^3} + \frac{2}{b^3}= a^2+ \frac{1}{b^3}= \frac{a^2b^3+1}{b^3} \\\ x^3+ \frac{1}{x^7}- \frac{1}{x^4} = \frac{x^{10}+1-x^3}{x^7}$