\(\left(x+\frac{-2}{9}\right)^3=\left(\frac{8}{27}\right)^2\\ \left(x+\frac{-2}{9}\right)^3=\left[\left(\frac{2}{3}\right)^3\right]^2\\ \left(x+\frac{-2}{9}\right)^3=\left(\frac{2}{3}\right)^{3\cdot2}\\ \left(x+\frac{-2}{9}\right)^3=\left[\left(\frac{2}{3}\right)^2\right]^3\\ \left(x+\frac{-2}{9}\right)^3=\left(\frac{4}{9}\right)^3\\ \Rightarrow x+\frac{-2}{9}=\frac{4}{9}\\ x=\frac{4}{9}+\frac{2}{9}\\ x=\frac{6}{9}=\frac{2}{3}\)
Vậy \(x=\frac{2}{3}\)
Cho C = 2/3 + 8/9 + 26/27 + ... + 3^n-1/3^n
Chứng ming rằng : C > n - 1/2
1)tim x bit a)(1/2-1/3).6^x+6^x+2=6^15+6^18
b)3^x+3^x+2=2430
c)(2x-15)^5=(2x-15)^3
2) so saanh a)2^11 va 5^35
b)2^31 va 3^21
c)2^15 va 27^5.49^8 d)21^15 va 27^5.49^8
1) Tính :
(95+273):38
2) Tìm x, biết:
32021-32019. x =32020
3)Hỏi A =1+2+22+23+.............+225 có chia hết cho 3 không ?
Biết 12 + 22 + 32 +....82 + 92 = 285. Tính 32 + 62 + 92 +.......242 + 272
tìm x , biết :
a, \(\dfrac{37-x}{2x+5}=\dfrac{4}{9}\)
b, \(\dfrac{x-2}{x-1}=\dfrac{x+4}{x+7}\)
c, \(\dfrac{x+3}{25}=\dfrac{9}{x+3}\)
d, \(\dfrac{x}{\dfrac{-2}{3}}=\dfrac{5}{-x}\)
e, \(\dfrac{2x-5}{\dfrac{3}{2}}=\dfrac{\dfrac{-27}{8}}{5-2x}\)
f, \(\dfrac{\dfrac{5}{9}}{\left(3x-1\right)^2}=\dfrac{1-2x}{\dfrac{25}{3}}\)
Tìm x biết:
a) \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
b) \(\left(x^4\right)^2=\dfrac{x^{12}}{x^5}\left(x\ne0\right)\)
c) \(\left(2x+3\right)^2=\dfrac{9}{121}\)
d) \(\left(2x-1\right)^3=\dfrac{-8}{27}\)
Tìm x:
a) 27x .9x = 927:81
b)\(\left(\dfrac{12}{25}\right)^x=\left(\dfrac{5}{3}\right)^{-2}-\left(\dfrac{-3}{5}\right)^4\)
Tìm x biết
a)\(\dfrac{x}{9}=\dfrac{16}{x}=\) b)\(x^3+27=0\) c)\(\left|x\left(x^2-\dfrac{5}{4}\right)\right|=x\) d)\(\left|x+3\right|+\left|x-5\right|=8\)
\(\frac{125^{2^{ }}.5^4}{25^{4^{ }}}\)
\(\frac{81^{2^{ }}.27^3}{9^8}\)
