![](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)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
1a) \(=-\left(x^3-3x^2+3x-1\right)=-\left(x-1\right)^3\)
b) \(=-\left(x^3-3x^2+3x-1\right)=-\left(x-1\right)^3\)
\(a,=-\left(x-1\right)^3\left[=\left(1-x\right)^3\right]\\ b,=\left(1-x\right)^3\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(x^3+3x^2+3x=-\dfrac{7}{8}\\ x^3+3x^2+3x+1=1-\dfrac{7}{8}\\ \left(x+1\right)^3=\dfrac{1}{8}\\ x+1=\dfrac{1}{2}\\ x=-\dfrac{1}{2}\)
Ta có: \(x^3+3x^2+3x=\dfrac{-7}{8}\)
\(\Leftrightarrow\left(x^3+3x^2+3x+1\right)=\dfrac{1}{8}\)
\(\Leftrightarrow\left(x+1\right)^3=\left(\dfrac{1}{2}\right)^3\)
\(\Leftrightarrow x+1=\dfrac{1}{2}\)
hay \(x=-\dfrac{1}{2}\)
Vậy: \(S=\left\{-\dfrac{1}{2}\right\}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(x^3+3x^2+3x=0\\ \Leftrightarrow x\left(x^2+3x+3\right)=0\\ \Leftrightarrow x=0\left(x^2+3x+3=x^2+3x+\dfrac{9}{4}=\left(x+\dfrac{3}{2}\right)^2+\dfrac{3}{4}>0\right)\)
\(x^3+3x^2+3x=0\)
\(\Rightarrow x\left(x^2+3x+3\right)=0\)
Mà: \(x^2+3x+3>0\)
=> x = 0
![](https://rs.olm.vn/images/avt/0.png?1311)
Bạn phải vt thêm dấu mũ vào mới giải đc chứ!! Để thế kia ai mà giải đc
![](https://rs.olm.vn/images/avt/0.png?1311)
\(x^3-3x^2+3x-1=\left(x-1\right)^3\)
Tại \(x=101\)
\(\Rightarrow\left(x-1\right)^3=\left(101-1\right)^3=100^3=1000000\)
\(x^3-3x^2+3x-1=x^3-1-3x^2+3x\)
\(=\left(x-1\right)\left(x^2+x+1\right)-3x\left(x-1\right)=\left(x-1\right)\left(x^2+x+1-x+1\right)\)
\(=\left(x-1\right)\left(x^2+2\right)\)Thay x = 101 ta được
\(=\left(101-1\right)\left(101^2+2\right)=100.10203=1020300\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a: Ta có: \(\left(x^2+2\right)\left(x-4\right)-\left(x+2\right)^3=-16\)
\(\Leftrightarrow x^3-4x^2+2x-8-x^3-6x^2-12x-8=-16\)
\(\Leftrightarrow-10x^2-10x=0\)
\(\Leftrightarrow-10x\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
c: Ta có: \(x^3+3x^2+3x+28=0\)
\(\Leftrightarrow\left(x+1\right)^3=-27\)
\(\Leftrightarrow x+1=-3\)
hay x=-4
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left(x^3-3x^2+3x-1\right)\)
\(=x^3-3x^2.1+3x.\left(-1\right)^2-1^3\)
\(=\left(x-1\right)^3\)
(x+a)3=x3+(a+a+a)x2+(a.a+a.a+a.a)x+a3
(x−1)3→a=−1
⇒(x−1)3=x3+(−1−1−1)x2+(1+1+1)x+(−1)3
=x3−3x2+3x−1
x3 + 3x2+3x+1=(x+1)3
Ta có
x3+3x2+3x+1=0⇔(x+1)3=0x3+3x2+3x+1=0⇔(x+1)3=0
⇔⇔ x + 1 = 0
⇔⇔ x = -1
Vậy x = -1