Помогите:)))))))))))))

2. а) $\frac{5^{n+1}-3*5^n}{2*5^{n-1}}= \frac{(5-3)*5^n}{2*5^{n-1}}= \frac{2*5}{2}=5$
б) $(0.125x^{-3}y^{-2})^2*( \frac{x^{-3}}{8y^2})^{-3}=(0.125*\frac{1}{x^3}* \frac{1}{y^2})^2*( \frac{1}{8y^2x^3})^{-3}=0.125^2*\frac{1}{x^6}* \frac{1}{y^4}*(8y^2x^3)^3=(\frac{125}{1000})^2*\frac{1}{x^6}* \frac{1}{y^4}*512y^6x^9=(\frac{1}{8})^2*512y^2x^3=\frac{1}{64}*512y^2x^3=8x^3y^2$