Question

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

при a=7,5

Answer 1

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