Tìm x biết:
\(2x^3-12x^2+18x=0\)
Tìm x biết:
\(2x^3-12x^2+18x=0\)
\(2x^3-12x^2+18x=0\)
\(x\left(2x^2-12x+18\right)=0\)
\(x[2\left(x-3\right)^2]=0\)
........
Tìm x:
a) x3-6x2+12x-8=\(\dfrac{-1}{1000}\)
b) x3-81x=0
c)x(7-2x)-7+2x=0
d)(9x2-x)-18x+2=0
tìm x biết : a) (x+1)2-(x-1)(x+1)=0 b) x3-5x2+4x-20=0 c) (3x+1)2-4(x-3)2=0 d) 2x3-12x2+18x=0 e)x2-2x-3=0 f)x2-9=2(x+3)2
Tìm x biết
12x2+18x=-2x3Tìm giá trị nhỏ nhất của đa thức A=3x2+2x+4 phần 3a) (2x-1)2-(x+3)=0
b) 2x3-12x2+18x=0
c) x3+5x2+4x+20=0
Tìm x
a) (12x-5)(3x-1)-(18x-1)(2x+3)=5
b) (x+2)(x-3)-(x-2)(x+5)=2(x+3)
c) (2x+3)(2x-1)-(2x+5)-(2x-3)=12
1) tim x: a) x(x+1) +3(x+1)=0 b) 3x(12x-4) -2x(18x+3) = 36
a) x(x+1)+3(x+1)=0
⇌ (x+1)(x+3)=0
\(\Rightarrow\left[{}\begin{matrix}x+1=0\\x+3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-1\\x=-3\end{matrix}\right.\)
b)3x(12x-4)-2x(18x+3)=0
⇒36x2-12x-36x2+6x=0
⇒ -6x = 0
⇒ x=0
DẠNG A^n=B^n
giải các phương trình sau
x^4= 24x^2 -144
x^4 =2x^2-12x+8
X^4-13^3+18x-5=0
x^3+3x^2-3x+1=0
a: \(\Leftrightarrow x^4-24x^2+144=0\)
\(\Leftrightarrow\left(x^2-12\right)^2=0\)
hay \(x=\pm2\sqrt{3}\)
b: \(\Leftrightarrow x^4-2x^2+12x-8=0\)
\(\Leftrightarrow\left(x^2-2x+4\right)\left(x^2+2x-2\right)=0\)
\(\Leftrightarrow x^2+2x-2=0\)
hay \(x\in\left\{-1+\sqrt{3};-1-\sqrt{3}\right\}\)
a)Thực hiện phép tính:(3x+1)(3x-1)-(18x^3+5x^2-2x):2x
b)Tìm x biết:3x(x-2021)-x+2021=0
\(a,\left(3x+1\right)\left(3x-1\right)-\left(18x^3+5x^2-2x\right):2x\\ =\left(9x^2-1\right)-\left(9x^2+\dfrac{5}{2}x-1\right)\\ =9x^2-1-9x^2-\dfrac{5}{2}x+1=\dfrac{5}{2}x\)
\(b,3x\left(x-2021\right)-x+2021=0\\ \Rightarrow b,3x\left(x-2021\right)-\left(x-2021\right)=0\\ \Rightarrow\left(x-2021\right)\left(3x-1\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=2021\\x=\dfrac{1}{3}\end{matrix}\right.\)