Question

$frac{a^{2} -10a+25}{a^{2} +5a} :frac{a-5}{a}$

при a=7,5

Answer 1

$frac{a^{2}-10a+25 }{a^{2}+5a }:frac{a-5}{a}=frac{(a-5)^{2}}{a(a+5)}*frac{a}{a-5}=frac{a-5}{a+5}\\frac{a-5}{a+5}=frac{7,5-5}{7,5+5}=frac{2,5}{12,5}=0,2$