Tìm x
\(3x^2-27x=0.\) Giúp Mk nha
bài 1 tìm x
3x (x - 2) - x +2 = 0
bài 2 tìm x
x^2 - 6x^2 +12x - 8 =0
16x^ - 9 (x +1)^2 =0
27+27x - 9x^2 +x^3=0
cac cậu giup mk voi mk cần gâp cho ngày mai
\(3x\left(x-2\right)-x+2=0\)
\(\Leftrightarrow3x\left(x-2\right)-\left(x-2\right)=0\)
\(\Leftrightarrow\left(3x-1\right)\left(x-2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x-1=0\\x-2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=2\end{cases}}\)
\(B1:\)
\(3x\left(x-2\right)-\left(x-2\right)=0\)
\(\left(3x-1\right)\left(x-2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3x-1=0\\x-2=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=2\end{cases}}\)
\(x^2-6x^2+12x-8=0\)
\(\Leftrightarrow\left(x-2\right)^3=0\)
\(\Leftrightarrow x-2=0\)
\(\Leftrightarrow x=2\)
tìm x: (3x-1)^2-16=0. m.n giúp mk vs nha:)))
(3x - 1 )2 - 16 =0
<=>(3x - 1 )2 = 16
<=>3x-1 =4
<=>x=5/3
(3x - 1)2 - 16 = 0
<=> (3x - 1)2 - 42 = 0
<=> (3x - 1 - 4)(3x - 1 + 4) = 0
<=> (3x - 5)(3x + 3) = 0
<=> 3x - 5 = 0 hoặc 3x + 3 = 0
<=> x = 5/3 hoặc x = - 1
(3x-1)^2-16=0
(3x-1)^2=16
Th1: 3x-1=4
3x=5
x=5/3
Th2: 3x-1=-4
3x=-3
x=-1
1) (x-1)3+(2x+3)3=27x3+8
2) 3x3+2x2+2x+3=0
Giúp mk vs!!!!!!!
\(3x^3+2x^2+2x+3=0\)
\(\Leftrightarrow3\left(x^3+1\right)+2x\left(x+1\right)=0\)
\(\Leftrightarrow3\left(x+1\right)\left(x^2-x+1\right)+2x\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(3x^2-x+3\right)=0\)
Mà \(3x^2-x+3=3\left[\left(x-\frac{1}{6}\right)^2+\frac{35}{36}\right]>0\forall x\)
Do đó: \(x+1=0\Leftrightarrow x=-1\)
Tập nghiệm: \(S=\left\{-1\right\}\)
\(\left(x-1\right)^3+\left(2x+3\right)^3=27x^3+8\)
\(\Leftrightarrow\left[\left(x-1\right)+\left(2x+3\right)\right]\left[\left(x-1\right)^2-\left(x-1\right)\left(2x+3\right)+\left(2x+3\right)^2\right]=27x^3+8\)
\(\Leftrightarrow\left(3x+2\right)\left(x^2-2x+1-2x^2-3x+2x+3+4x^2+12x+9\right)=27x^3+8\)
\(\Leftrightarrow\left(3x+2\right)\left(3x^2+9x+13\right)=\left(3x+2\right)\left(9x^2-6x+4\right)\)
\(\Leftrightarrow\left(3x+2\right)\left(6x^2-15x-9\right)=0\)(Chuyển vế)
\(\Leftrightarrow3\left(3x+2\right)\left(2x^2-5x-3\right)=0\)
\(\Leftrightarrow3\left(3x+2\right)\left(x-3\right)\left(2x+1\right)=0\)
Tập nghiệm: \(S=\left\{-\frac{2}{3};3;-\frac{1}{2}\right\}\)
Giải phương trình giúp em ạ 27x^2(x+3)-12(x^2+3x)=0
tìm x,biết
a) 3x2 - 27x = 0
b) 2/3x ( x2 - 4) = 0
a, 3x^2-27x=0
3x(x-9)=0
3x=0=>x=0
x-9=0=>x=9
b,2/3x(x^2-4)=0
2/3x=0=>x=0
x^2-4=0=>x=2
tìm x,biết
a) 3x2 - 27x = 0
b) 2/3x ( x2 - 4) = 0
\(3x^2-27x=0\)
\(3x\left(x-9\right)=0\)
\(\left[\begin{array}{nghiempt}x=0\\x-9=0\end{array}\right.\)
\(\left[\begin{array}{nghiempt}x=0\\x=9\end{array}\right.\)
\(\frac{2}{3}x\left(x^2-4\right)=0\)
\(\frac{2}{3}x\left(x-2\right)\left(x+2\right)=0\)
\(\left[\begin{array}{nghiempt}x=0\\x-2=0\\x+2=0\end{array}\right.\)
\(\left[\begin{array}{nghiempt}x=0\\x=2\\x=-2\end{array}\right.\)
a)\(3x^2-27x=0\)
\(3x\left(x-9\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}3x=0\\x-9=0\end{array}\right.\Rightarrow\left[\begin{array}{nghiempt}x=0\\x=9\end{array}\right.\)
b) \(\frac{2}{3}x\left(x^2-4\right)=0\)
\(\frac{2}{3}x\left(x+2\right)\left(x-2\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}\frac{2}{3}x=0\\x+2=0\\x-2=0\end{array}\right.\Rightarrow\left[\begin{array}{nghiempt}x=0\\x=-2\\x=2\end{array}\right.\)
x2-27x-64 =0
giúp mk nha
Ta có: \(x^2-27x-64=0\)
\(\Leftrightarrow x^2-2\cdot x\cdot\frac{27}{2}+\frac{729}{4}-\frac{985}{4}=0\)
\(\Leftrightarrow\left(x-\frac{27}{2}\right)^2=\frac{985}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}x-\frac{27}{2}=\sqrt{\frac{985}{4}}\\x-\frac{27}{2}=-\sqrt{\frac{985}{4}}\end{matrix}\right.\)\(\left[{}\begin{matrix}x=\sqrt{\frac{985}{4}}+\frac{27}{2}=\frac{27+\sqrt{985}}{2}\\x=-\sqrt{\frac{985}{4}}+\frac{27}{2}=\frac{27-\sqrt{985}}{2}\end{matrix}\right.\)
Vậy: \(x=\frac{27\pm\sqrt{985}}{2}\)
Viết bt sau dưới dạng tích :
a)27x3-27x2+3x+1
b)x3-3x2+3x-1
c)0,001-1000x3
TT giúp mik nha
bài 1 ; tìm x bt
a,3.(x+3)-2.(x-5)=11
b,14-4./x/=-6
bài 2 tìm x,y nguyên biết
a,(x-2).(6+y)=(-19)
b,2xy - 3x +20= 0
c, xy+2y+3x+15=0
giúp mk nha, mk cần gấp
a, 3(x+3)-2(x-5)=11
=> 3x+9-2x+10=11
=> 3x-2x=11-10-9
=> x=-8
Vậy.........
b, 14-4|x|=-6
=> -4|x|=8
=> |x|=-2(VL vì trị tuyệt đối luôn lớn hơn hoặc = 0)
Vậy......