Question

Помогите решить №11 и №20

Answer 1

Решение во вложении:

Answer 2

$\frac{\frac{3y^{2} }{x^{2}}-\frac{2xy}{x^{2}} +\frac{x^{2}}{x^{2}}}{\frac{x^{2}}{x^{2}}+\frac{xy}{x^{2}} +\frac{y^{2}}{x^{2}}}=\frac{3(\frac{y}{x})^{2}-2\frac{y}{x}+1}{1+\frac{y}{x}+(\frac{y}{x})^{2}}=\frac{3*9-2*3+1}{1+3+9}=\frac{22}{13}$

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