Tìm x biết: |-2|.(x+4-|x-1|)=2+2x
Tìm x biết
(x+2)(x^2-2x+4)-x(x-1)(x+1)+2x=2
(x+2)(x^2-2x+4)-x(x-1)(x+1)+2x=2
<=> x3 - 2x2 + 4x + 2x2 - 4x + 8 - x(x2 - 1) + 2x = 2
<=> x3 + 8 - x3 + x + 2x = 2
<=> 3x + 8 = 2
<=> x = -2
PT \(\Rightarrow2x^2+2x-3x-6=2x^2-x+4x-8-2\)
\(\Rightarrow-4x=-4\) \(\Leftrightarrow x=1\)
Vậy \(x=1\)
Ta có: \(2x\left(x+1\right)-3\left(x+2\right)=x\left(2x-1\right)+4\left(x-2\right)-2\)
\(\Leftrightarrow2x^2+2x-3x-6=2x^2-x+4x-8-2\)
\(\Leftrightarrow2x^2-x-6=2x^2+3x-10\)
\(\Leftrightarrow2x^2-x-6-2x^2-3x+10=0\)
\(\Leftrightarrow-4x+4=0\)
\(\Leftrightarrow-4x=-4\)
hay x=1
Vậy: x=1
Tìm x biết:
a) ( x – 1 ) 3 + ( 2 – x ) ( 4 + 2 x + x 2 ) + 3x(x + 2) = 16;
b) (x + 2)( x 2 – 2x + 4) – x( x 2 – 2) = 15.
a) Rút gọn được VT = 9x + 7. Từ đó tìm được x = 1.
b) Rút gọn được VT = 2x + 8. Từ đó tìm được x = 7 2 .
5: Tìm x biết a) x/3 =4/12 b) x-1/ x-2=3/5 c) 2x :6=1/4 d) x² +x/2x²+1=1/2
a) \(\dfrac{x}{3}=\dfrac{4}{12}\Rightarrow x=\dfrac{4}{12}\cdot3=\dfrac{12}{12}=1\)
b) \(\dfrac{x-1}{x-2}=\dfrac{3}{5}\) (Điều kiện : \(x\ne2\))
\(\Rightarrow5\left(x-1\right)=3\left(x-2\right)\)
\(\Leftrightarrow5x-5=3x-6\Leftrightarrow5x-3x=-6+5\Leftrightarrow2x=-1\Leftrightarrow x=-\dfrac{1}{2}\)
c) \(2x:6=\dfrac{1}{4}\Leftrightarrow2x=\dfrac{1}{4}\cdot6=\dfrac{6}{4}=\dfrac{3}{2}\Leftrightarrow x=\dfrac{3}{2}:2=\dfrac{3}{2}\cdot\dfrac{1}{2}=\dfrac{3}{4}\)
d) \(\dfrac{x^2+x}{2x^2+1}=\dfrac{1}{2}\)
\(\Rightarrow2\left(x^2+x\right)=2x^2+1\)
\(\Leftrightarrow2x^2+2x=2x^2+1\)
\(\Leftrightarrow2x^2+2x-2x^2=1\Leftrightarrow2x=1\Leftrightarrow x=\dfrac{1}{2}\).
Tìm x biết (x+2)(x^2-2x+4)=(x-1)^3+3(x+1)^2
\((x+2)(x^2-2x+4)=(x-1)^3+3(x+1)^2\\\Leftrightarrow x^3+2^3=x^3-3x^2+3x-1+3\cdot(x^2+2x+1)\\\Leftrightarrow x^3 +8=x^3-3x^2+3x-1+3x^2+6x+3\\\Leftrightarrow x^3-x^3 +3x^2-3x-3x^2-6x=-1+3-8\\\Leftrightarrow -9x=-6\\\Leftrightarrow x=\dfrac{2}{3}\)
Vậy \(x=\dfrac{2}{3}\)
Tìm x, biết:
a) 8x(x - 2017) - 2x + 4034 = 0; b) x 2 + x 2 8 = 0;
c) 4 - x = 2 ( x - 4 ) 2 ; d) ( x 2 + 1)(x - 2) + 2x = 4.
Tìm x biết a) x(x-25)=0 b)2x(x-4)-x(2x-1)=-28 c)x^2 -5x=0 d)(x-2)^2-(x+1)(x+3)=-7 e)(3x+5).(4-3x)=0 f)x^2-1/4=0
a: \(x\in\left\{0;25\right\}\)
c: \(x\in\left\{0;5\right\}\)
tìm x biết (x-1)^4/(x^2-3)^2 +(x^2-3)^2 + 1/(x-1)^4 = 3x^2 -2x - 5
Tìm x biết \(2x^4-2x^2+4x^5+3x^2-x+x^2+1-x^4-2x^{2+1+2}=5\)
1. Tìm số nguyên x, y biết,
(x + 2)2 + (y -4)2 + (2y -4)4 = 0
2. Tìm số nguyên x, biết
x2 - 2x = 3
\(1,\)
\(\left(x+2\right)^2\ge0;\left(y-4\right)^2\ge0;\left(2y-4\right)^2\ge0\\ \Leftrightarrow\left(x+2\right)^2+\left(y-4\right)^2+\left(2y-4\right)^2\ge0\)
Dấu \("="\Leftrightarrow\left\{{}\begin{matrix}x=-2\\y=4\\y=2\end{matrix}\right.\left(vô.lí\right)\)
Do đó PT vô nghiệm
\(2,\Leftrightarrow x^2-2x-3=0\Leftrightarrow x^2+x-3x-3=0\\ \Leftrightarrow\left(x+1\right)\left(x-3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=3\end{matrix}\right.\)