Tìm x biết : x^2 -x +27=0
Tìm x biết: 4x².(x-2)-x+2=0 x³+27+(x+3).(x-9)
\(x^3+27+\left(x+3\right)\left(x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-2x\right)=0\)
\(\Leftrightarrow x\left(x+3\right)\left(x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-3\end{matrix}\right.\)
a: Ta có: \(4x^2\left(x-2\right)-x+2=0\)
\(\Leftrightarrow\left(x-2\right)\left(4x^2-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{1}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)
b: Ta có: \(x^3+27+\left(x+3\right)\left(x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9+x-9\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=0\\x=2\end{matrix}\right.\)
Tìm x biết:
a. x3 – 25x = 0 b. 3x(x- 2) – x + 2 = 0
c. x2 – 4x - 5 = 0 d.x3 – x2 + 3x – 3 = 0
e. x3 + 27 + ( x + 3)( x – 9) = 0
a: \(\Leftrightarrow x\left(x-5\right)\left(x+5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\\x=-5\end{matrix}\right.\)
Tìm x, biết:
a) 3x(x - 1) + x - 1 = 0;
b) (x - 2)( x 2 + 2x + 7) + 2( x 2 - 4) - 5(x - 2) = 0;
c) ( 2 x - 1 ) 2 - 25 = 0;
d) x 3 + 27 + (x + 3)(x - 9) = 0.
a) x = 1; x = - 1 3 b) x = 2.
c) x = 3; x = -2. d) x = -3; x = 0; x = 2.
tìm số nguyên x , biết :
a) x + 546 = 46
b) 2x - 19 x 3 = 27
c) x + 12= 23 + 3 x 3^4
d) x- 12 = 3 - 3 x 2^4
e) ( 27 - x ) nhân ( x +9 ) = 0
f) ( -x) x ( x-43) = 0
a) \(x+546=46\\ x=46-546\\ x=-500\)
b) \(2x-19\times3=27\\ 2x-57=27\\ 2x=27+57\\ 2x=84\\ x=84:2\\ x=42\)
c) \(x+12=23+3\times3^4\\ x+12=23+3\times81\\ x=23+243-12\\ x=254\)
d) \(x-12=3-3\times2^4\\ x-12=3-3\times16\\ x=3-48+12\\ x=-33\)
e) \(\left(27-x\right)\left(x+9\right)=0\\ \Rightarrow\left[{}\begin{matrix}27-x=0\\x+9=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=27\\x=-9\end{matrix}\right.\)
f) \(\left(-x\right)\left(x-43\right)=0\\ \Rightarrow\left[{}\begin{matrix}-x=0\\x-43=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=43\end{matrix}\right.\)
a) x + 546 = 46
x = 46 - 546
x = -500
b) 2x - 19 x 3 = 27
2x - 57 = 27
2x = 27 + 57
2x = 84
x = 84 : 2
x = 42
c) x + 12 = 23 + 3 x 34
x + 12 = 23 + 3 x 81
x + 12 = 23 + 243
x + 12 = 266
x = 266 - 12
x = 254
d) x - 12 = 3 - 3 x 24
x - 12 = 3 - 3 x 16
x - 12 = 3 - 48
x - 12 = -45
x = -45 + 12
x = -33
e) (27 - x) x (x + 9) = 0
TH1: 27 - x = 0
x = 27 - 0
x = 27
TH2: x + 9 = 0
x = 0 + 9
x = 9
⇒ x = 27 hoặc x = 9
f) (-x) x (x - 43) = 0
TH1: -x = 0
⇒ x = 0
TH2: x - 43 = 0
x = 0 + 43
x = 43
⇒ x = 0 hoặc x = 43.
Tìm x biết :
1) ( 2x - 1 )^2 - ( x + 3 )^2 = 0
2) x^3 + 27 + ( x + 3 ) ( x - 9 ) = 0
\(\left(2x-1\right)^2-\left(x+3\right)^2=0\)
\(\Leftrightarrow\left(2x-1-x-3\right)\left(2x-1+x+3\right)=0\)
\(\Leftrightarrow\left(x-4\right)\left(3x+2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-4=0\\3x+2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=4\\x=-\frac{2}{3}\end{cases}}}\)
\(x^3+27+\left(x+3\right)\left(x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9+x-9\right)=0\)
\(\Leftrightarrow\left(x+3\right)\left(x^2-2x\right)=0\)
\(\Leftrightarrow x\left(x+3\right)\left(x-2\right)=0\)
\(\Leftrightarrow\hept{\begin{cases}x=0\\x+3=0\\x-2=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=0\\x=-3\\x=2\end{cases}}}\)
tìm x biết:\(\frac{x^2}{-8}=\frac{27}{x}\)(x khác 0)
x2/ -8 = 27/x
x2. x = -8.27
x3 = -216
x3= -63
=> x= -6
Vậy....
\(\frac{x^2}{-8}=\frac{27}{x}\)
\(\Rightarrow x^2.x=\left(-8\right).27\)
\(x^3=-216\)
\(x^3=\left(-6\right)^3\)
\(x=-6\)
Vậy \(x=-6\)
Tìm x,y biết:
1) 3^X-1 = 1/243
2) 81^-2X x 27^X=9^5
3) ( x-y+3)^2 + (y-1)^2=0
Tìm x biết 2(x+3)-x^2-3x=0
x^3+27+(x+3)(x-9)=0
4x^2-25-(2x-5)(2x+7)=0
8x^3-50x=0
(2x-1)^2-25=0
Tìm số nguyên x biết:
a) x(x+7)=0
b) (3x+9)(x2-16)=0
c) (x-3)(x3+27)=0
d)x(x-2)<0