1) 5^(x-4) < 25
5^(x-4)< 5^2
x-4<2; x<6; x∈(-∞;6)<br>----------------------------
3^(3x+1) > 1/81
3^(3x+1) > 3^(-4)
3x+1 > -4
3x>-5; x> -5/3; x∈(-1 2/3; +∞)
2) 5^(x²-11) > 1/25
5^(x²-11) >5^(-2)
x²-11>-2
x²>9 ; x<-3 и x>3; x∈(-∞;-3)∪(3;+∞)
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2^(4-x) ≤8
2^(4-x) ≤2^3
4-x<3<br>1x>1; x∈(1;+∞)
3) 5^(x+1) -5^x ≥ 100
5^x (5-1) ≥100
5x ≥100:4
5x≥25
x≥5 ; x∈[5;+∞)
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3^(x+2) -2*3^x= 7
3^x (3²-2) =7
7*3^x=7
3^x=1
x=0²