125^x-25^x+(4*25^x-20)/5^x-5amp;lt;=4

5^x=a
a-a+(4a-20)/(a-5) -40
(a^4-5a-a+5a+4a-20-4a+20)/(a-5)0
(a^4-6a+10a-4a)/(a-5)0
a(a-6a+10a-4)/(a-5)0
a[a(a-2)-4a(a-2)+2(a-2)]/(a-5)0
a(a-2)(a-4a+2)/(a-5)0
a=0
a-2=0a=2
a-4a+2=0
D=16-8=8
a1=(4-22)/2=2-2
a2=2+2
a-5=0a=5
           _                +              _                +              _              +
--------------[0]-----------[2-2]---------[2]---------[2+2]--------(5)-----------
alt;05^xlt;0нет решения
2-2a22-25^x2log(5)(2-2)xlog(5)2
2+2alt;52+25^xlt;5log(5)(2+2)xlt;1
x[log(5)(2-2);log(5)2] U [log(5)(2+2);1)