Question

помогите пожалуйстааа

Answer 1

$frac{2cdot 9^{a}-3cdot 15^{a}-25^{a}}{2cdot 9^{a}-7cdot 15^{a}-3cdot 25^{a}}=frac{2cdot 3^{2a}-3cdot 3^{a}cdot 5^{a}-5^{2a}}{2cdot 3^{2a}-7cdot 3^{a}cdot 5^{a}-3cdot 5^{2a}}=frac{3^{2a}cdot ; (2-3cdot (frac{5}{3})^{a}-(frac{5}{3})^{2a})}{3^{2a}cdot ; (2-7cdot (frac{5}{3})^{a}-3cdot (frac{5}{3})^{2a})}=\\=[, t=(frac{5}{3})^{a}>0; ]=frac{2-3t-t^2}{2-7t-3t^2}=frac{t^2+3t-2}{3t^2+7t-2}=frac{1}{4}; ; Rightarrow \\4(t^2+3t-2)=3t^2+7t-2\\4t^2+12t-8-3t^2-7t+2=0\\t^2+5t-6=0$

$t_1=-6; ,; ; t_2=1; ; (teorema; Vieta)\\(frac{5}{3})^{a}=-6<0; ; ne; ; podxodit\\(frac{5}{3})^{a}=1; ; Rightarrow ; ; ; frac{5^{a}}{3^{a}}=1$