![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(\frac{3}{5}-\frac{2}{3}x\right)^3=\frac{-64}{125}=\left(\frac{-4}{5}\right)^3\)
=> \(\frac{3}{5}-\frac{2}{3}x=\frac{-4}{5}\)
=> \(\frac{2}{3}x=\frac{3}{5}-\frac{-4}{5}\)
=> \(\frac{2}{3}.x=\frac{3}{5}+\frac{4}{5}=\frac{7}{5}\)
=> \(x=\frac{7}{5}:\frac{2}{3}\)
=> \(x=\frac{7}{5}.\frac{3}{2}=\frac{21}{10}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\dfrac{-64}{125}\)
\(\rightarrow\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\left(\dfrac{-4}{5}\right)^3\)
\(\rightarrow\dfrac{3}{5}-\dfrac{2}{3}x=\dfrac{-4}{5}\)
\(\rightarrow x=\dfrac{21}{10}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(x+5\right)^3=\dfrac{-64}{125}\)
\(\Rightarrow\left(x+5\right)^3=\left(\dfrac{-4}{5}\right)^3\)
\(\Rightarrow x+5=-\dfrac{4}{5}\)
\(\Rightarrow x=-\dfrac{4}{5}-5\)
\(\Rightarrow x=-\dfrac{29}{5}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có : 3x + 3x + 2 = 810
=> 3x(1 + 32) = 810
=> 3x.10 = 810
=> 3x = 81
=> 3x = 34
=> x = 4
ta có \(3^3+3^x+2=810\)
=>\(3^x\left(1+3^2\right)=810\)
=>\(3^x.10=810\)
=>\(3^x=81\)
=>\(3^x=3^4\)
=>x=4
Vậy x=4
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a. VP: \(\left(x+y\right)^{1999}\cdot\left(x-y\right)^{1999}=\left[\left(x+y\right)\left(x-y\right)\right]^{1999}\)
\(=\left(x^2-xy+xy-y^2\right)^{1999}=\left(x^2-y^2\right)^{1999}=VT\)
--> đpcm
b. VT: \(\dfrac{\left(5^4-5^3\right)^3}{125^4}=\dfrac{500^3}{125^4}=\dfrac{125^3\cdot4^3}{125^4}=\dfrac{4^3}{125}=\dfrac{64}{125}=VP\)
--> đpcm
![](https://rs.olm.vn/images/avt/0.png?1311)
(3/5-2/3.x)3=-64/125
(3/5-2/3.x)3=(-4/5)3
3/5-2/3.x=-4/5
2/3.x=3/5-(-4/5)
2/3.x=7/5
x=7/5:2/3
x=21/10