\(\left(\frac{3^x}{3}\right)^2=\frac{1}{729}\Rightarrow3^{x-1}=\frac{1}{27}\Rightarrow x-1=-3\Rightarrow x=-2\)
x = -2 nhé bn
tích mk nha các bn
>_< học tốt
tìm x biết : a,\(\frac{x^7}{81}=27\); b,\(\frac{x^8}{9}=729\); c.\(^{\left[x-\frac{1}{2}\right]^0}\); d,\(\left[X-2\right]^2=1\); e, \(\left[2X-1\right]^3=8\); f,\(\left[X+\frac{1}{2}\right]^2\)=\(\frac{1}{16}\)
1. Tìm x\(\inℚ\), biết:
a)\(\left(x-\frac{1}{2}\right)2=0\)
b)\(\left(x-2\right)^2=1\)
c) \(\left(2x-1\right)^3=-8\)
d)\(\left(x+\frac{1}{2}\right)^2=\frac{1}{16}\)
e)\(\frac{x^7}{81}=27\)
g)\(\frac{x^8}{9}=^{729}\)
Baif 1
a)\(\frac{1}{42}.16^x=8^x\)
b)\(3^{-3}.3^5.3^x=3^8\)
c)\(\left(7x+2\right)^{-1}=3^{-2}\)
Bài 2
a)\(3^4.\frac{1}{729}.81^3.\frac{1}{9^2}\)
b)\(\left(8.2^5\right):\left(2^4.\frac{1}{32}\right)\)
c)\(12^8.9^{12}\)
d)\(\left(1+\frac{2}{3}-\frac{1}{4}\right).\left(\frac{4}{5}-\frac{3}{4}\right)^2\)
Giups mik nha
Bài 1: Tìm x
a) \(\left(x-2\right)^4=256\)
b) \(\frac{x^4}{256}=81\)
c) \(125\left(x+\frac{4}{5}\right)^3=729\)
e) \(7^x+2+7x=50\)
f) \(9.13^{x-1}+\frac{4}{169}.13^{x+1}=2197\)
tìm x
\(\frac{4}{5}x^2\left(\frac{x}{3}-\frac{1}{2}\right)-\left(\frac{1}{2}x-\frac{2}{3}\right)\left(\frac{4x^2}{3}+1\right)=\frac{22}{45}x^2\)
1. Tìm x ϵ Q sao cho:
a) (2x-3). (x+1) < 0.
b) \(\left(x-\frac{1}{2}\right).\left(x+3\right)>0\)
2.Tính:
S=\(\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{999.1001}\)
3.Tìm x: Biết x không thuộc{-2; -5; -10; -17}
\(\frac{3}{\left(x+2\right).\left(x+5\right)}+\frac{5}{\left(x+5\right).\left(x+10\right)}+\frac{7}{\left(x+10\right).\left(x+17\right)}=\frac{x}{\left(x+2\right).\left(x+17\right)}\)
Tìm X: \(\frac{\left(x+1\right)^2-\frac{x}{2}}{4}=\frac{\left(2x-3\right)^2}{3}-\frac{\frac{x+1}{4}-\frac{x\left(3-2x\right)}{3}}{4}\)
TÌM x
\(\left(\left(\frac{3}{4}\cdot x+5\right)-\left(\frac{2}{3}\cdot x-4\right)-\left(\frac{1}{6}\cdot x+1\right)\right)=\left(\frac{1}{3}\cdot x+4\right)-\left(\frac{1}{3}-3\right)\)
Tìm x::\(\frac{1}{x\left(x+1\right)}+\frac{1}{\left(x+1\right)\left(x+2\right)}+\frac{1}{\left(x+2\right)\left(x+3\right)}-\frac{1}{x}=\frac{1}{2010}\)