3^x ×3^4+3^ -(x+3)>4
81 ×3^x+1/3^(x+3)>4
81×3^x+1/(3^x *3³)>4
81* 3^x+1/27*3^x-4>0
3^x=t
81 t+1/27t -4>0
2187t²-108t+1>0
y=2187t²-108t+1
2187t²-108t+1=0
D1=2916-2187=729
t1=54+27=81 t2=54-27=27
____+______27____-_____81___+_______
t>81 t<27<br>3^x>81 3^x<27<br>3^x>3^4 3^x<3³<br>x>4 x<3<br>
8^x+2^4/2^3x≥17
8^x +16/(2³)^x≥17
8^x+16/8^x-17≥0
8^x=t
t+16/t -17≥0
t²-17t+16≥0
y=t²-17t+16
t²-17t+16=0
D=289-64=225
t1=(17+15)/2=16 t2=(17-15)/2=1
t∈(-∞ 1]∨[16 ∞)
8^x≤1 8^x≥16
x≤0 2^(3x)≥2^4
3x≥4
x≥4/3