Question

Решите неравенство $9^x-8*6^x+15*4^x \leq 0$

Answer 1

9^x-8^3^x*2^x+15*4^x≤0/4^x
(3/2)^2x-8*(3/2)^x+15≤0
(3/2)^x=a
a²-8a+15≤0
a1+a2=8 U a1*a2=15
a1=3 U a2=5
3≤a≤5
3≤(3/2)^x≤5
x∈[log(3/2)3;log(3/2)5]