2x +I xI = 3x
tim x biet :
a) ( 2x^2+4 ) - (x^2-3/2 ) = (-3+4x^2)+ ( -4x^2/3+1)
b) ( I xI -4) - ( 2- I-xI ) = 1/3 . I xI -5
tim x biet :
a) ( 2x2+4 ) - (x2-3/2 ) = (-3+4x2)+ ( -4x2/3+1)
b) ( I xI -4) - ( 2- I-xI ) = 1/3 . I xI -5
Không có ngiệm nguyên hay hữu tỉ mà bạn
tim x biet :
a) ( 2x2+4 ) - (x2-3/2 ) = (-3+4x2)+ ( -4x2/3+1)
b) ( I xI -4) - ( 2- I-xI ) = 1/3 . I xI -5
tim x biet :
a) ( 2x2+4 ) - (x2-3/2 ) = (-3+4x2)+ ( -4x2/3+1)
b) ( I xI -4) - ( 2- I-xI ) = 1/3 . I xI -5
a: \(\Leftrightarrow2x^2+4-x^2+\dfrac{3}{2}=-3+4x^2-\dfrac{4}{3}x^2+1\)
\(\Leftrightarrow x^2+\dfrac{11}{2}=\dfrac{8}{3}x^2-2\)
\(\Leftrightarrow x^2\cdot\dfrac{-5}{3}=-\dfrac{15}{2}\)
\(\Leftrightarrow x^2=\dfrac{9}{2}\)
hay \(x\in\left\{\dfrac{3\sqrt{2}}{2};-\dfrac{3\sqrt{2}}{2}\right\}\)
b: \(\Leftrightarrow\left|x\right|-4-2+\left|x\right|-\dfrac{1}{3}\left|x\right|+5=0\)
\(\Leftrightarrow\left|x\right|\cdot\dfrac{5}{3}=1\)
hay \(x\in\left\{\dfrac{3}{5};-\dfrac{3}{5}\right\}\)
tim x biet :
a) ( 2x2+4 ) - (x2-3/2 ) = (-3+4x2)+ ( -4x2/3+1)
b) ( I xI -4) - ( 2- I-xI ) = 1/3 . I xI -5
\(2x^2+4-\left(x^2-\frac{3}{2}\right)=\left(-3+4x^2\right)+\left(-\frac{4x^2}{3}+1\right)\)
\(2x^2-x^2+4+\frac{3}{2}=\)\(-3+1+4x^2-\frac{4x^2}{3}\)
\(x^2+\frac{11}{2}=-2+-\frac{16x^2}{3}\)
\(x^2+\frac{16x^2}{3}=\frac{-11}{2}-2=-\frac{15}{2}\)
\(\frac{19x^2}{3}=-\frac{15}{2}\)
\(19x^2=\frac{-15}{2}.3=-\frac{45}{2}\)
\(x^2=\frac{-45}{2}:19=-\frac{45}{38}\)
tìm x: I 4-xI + 2x = 3
các bn giúp mk
| 4 - x | + 2x = 3
=> | 4 - x | = 3 - 2x
\(\Rightarrow\orbr{\begin{cases}4-x=3-2x\\4-x=2x-3\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}-x+2x=3-4\\x-2x=3-4\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=-1\\-x=-1\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=-1\\x=1\end{cases}}\)
Vậy \(x=\pm1\)
@@ Học tốt
* Với \(x\le4\)
=> \(\left|4-x\right|+2x=4-x+2x=3\)\(\Rightarrow x=-1\left(TM\right)\)
*Với \(x>4\)
\(\Rightarrow\left|4-x\right|+2x=-4+x+2x=3\Rightarrow3x=7\Rightarrow x=\frac{7}{3}\left(TM\right)\)
Vậy\(x\in\left\{-1;\frac{7}{3}\right\}\)
Sr nhé
T làm sai TH2
Bạn @peekQwQ. làm đúng r đó
Xl nha
Tìm x:
a,I2xI=3-x
b,Ix-1I=2x-1
c,I9-xI-9=3x
d,I3x-1I+2=x
e,I3x-5I+x=2
a) \(\left|2x\right|=3-x\)
\(\Rightarrow\orbr{\begin{cases}2x=3-x\\2x=x-3\end{cases}}\Rightarrow\orbr{\begin{cases}2x+x=3\\2x-x=-3\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}3x=3\\x=-3\end{cases}}\Rightarrow\orbr{\begin{cases}x=1\\x=-3\end{cases}}\)
b) \(\left|x-1\right|=2x-1\)
\(\Rightarrow\orbr{\begin{cases}x-1=2x-1\\x-1=1-2x\end{cases}}\Rightarrow\orbr{\begin{cases}x-2x=-1+1\\x+2x=1+1\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}-x=0\\3x=2\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x=\frac{2}{3}\end{cases}}\)
Mình làm mẫu câu a) nhé
Do |2x|>hoặc =0
=>3-x.hoặc =0
=>x<hoặc =3 (1)
Mà |2x| chẵn với mọi x
=>3-x là số chẵn
=>x lẻ (2)
Từ (1) và (2) ta có :
x thuộc {1;3}
+Nếu x=1=>|2x|=2
3-x=2 (t/mãn)
+Nếu x=3=>|2x|=6
3-x=0 (loại)
Vậy x =1
I 7+5x I = 1-4x
I 4x^2 - 2x I + 1 = 2x
I x^2 - 5x + 4 I = x+4
I 4 - 3x I = 3x -4
I 1+5x I = 1 + 5x
I x^2 - 3x + 1 I = 2x-3
I x-1 I = x^2 -x
|7 + 5x| = 1 - 4x
=> \(\orbr{\begin{cases}7+5x=1-4x\left(đk:x\le\frac{1}{4}\right)\\7+5x=4x-1\left(đk:x\ge\frac{1}{4}\right)\end{cases}}\)
=> \(\orbr{\begin{cases}7-1=-4x-5x\\7+1=4x-5x\end{cases}}\)
=> \(\orbr{\begin{cases}6=-9x\\8=-x\end{cases}}\)
=> \(\orbr{\begin{cases}x=-\frac{2}{3}\left(tm\right)\\x=-8\left(ktm\right)\end{cases}}\)
|4x2 - 2x| + 1 = 2x
=> |4x2 - 2x| = 2x - 1
=> \(\orbr{\begin{cases}4x^2-2x=2x-1\left(đk:x\ge\frac{1}{2}\right)\\4x^2-2x=1-2x\left(đk:x\le\frac{1}{2}\right)\end{cases}}\)
=> \(\orbr{\begin{cases}4x^2-2x-2x+1=0\\4x^2-2x-1+2x=0\end{cases}}\)
=> \(\orbr{\begin{cases}\left(2x-1\right)^2=0\\4x^2-1=0\end{cases}}\)
=> \(\orbr{\begin{cases}2x-1=0\\x^2=\frac{1}{4}\end{cases}}\)
=> \(\orbr{\begin{cases}x=\frac{1}{2}\\x=\pm\frac{1}{2}\end{cases}}\)(tm)
Vậy ...
tim x :
a) I x+1I+I x -2I+I x+3I = 6
b) 2Ix+2I+I4-xi= 11
c) IxI - I 2x+3I = x-1