Ta có: \(\left(\frac{2}{5}\right)^x>\left(\frac{2}{5}\right)^3\cdot\left(-\frac{2}{5}\right)^2\)
\(\Leftrightarrow\left(\frac{2}{5}\right)^x>\left(\frac{2}{5}\right)^3\cdot\left(\frac{2}{5}\right)^2\)
\(\Leftrightarrow\left(\frac{2}{5}\right)^x>\left(\frac{2}{5}\right)^5\)
\(\Leftrightarrow x< 5\)
Vậy x < 5
1)tim x biet rang:
a)3^x-1=1/243
b)2^x+2^x+3=144
c)81^-2x.27x=9^5
2)tim tiep so ghang thu 5 cua day so sau:-1/a^2;2/a^3;-6/a^4;24/a^5;...
3)tim so tu nhien x biet :
a)4^x+4^x+3=4160
b)2^x-1+5.2^x-2=7/32
Tim x biet(4x-3)-(x+5)=(x+2)-2×(x-10)
tim x biet 5/4*(x-8)=-5/3(14-1/2)
tim x va y biet
y\2=2\5+3.x=1\5+y
tim x biet (x^2-1)(x^2-3)(x^2-5)(x^2-7)<=0
Tim x biet 2.(x-3)-3.(x-1)-5
tim x biet :3/[x+2][x+5]+5[x+5][x+10]+7/[x+10][x+15]=x/[x+12][x+17]
tim x biet
3/(x+2).(x+5) + 5/(x+5).(x+10) + 7/(x+10).(x+17) = x/(x+2).(x+17)
Với x thuộc tập hợp A = -2;-5;-10;-17
tim x biet (2x-3)^2-4(x+1)^2=5
