Обозначим 5^x=a
(a²-25a+26)/(a-1)+(a²-7a+1)/(a-7)-(2a-24)≤0
[(a²-25a+26))(a-7)+(a²-7a+1)(a-1)-(2a-24)(a²-8a+7)]/[(a-1)(a-7)]≤0
(a³-7a²-25a²+175a+26a-182+a³-7a²+a-a²+7a-1-2a³+16a²-14a+24a²-192a+168)/
[(a-1)(a-7)]≤0
(3a-15)/[(a-1)(a-7)]≤0
a=5 a=1 a=7
_ + _ +
-------(1)------------[5]---------(7)--------
a<1⇒5^x<1⇒x<0<br>5≤a<7⇒5≤5^x<7⇒1≤x<log(5)7<br>x∈(∞;0) U [1;log(5)7)