1. tim x biet
\(\left|x-3\right|-\left|x+1,5\right|=0\)
tim x biet
\(\left(x-\frac{1}{3}\right).\left(y-\frac{1}{2}\right).\left(z-5\right)=0\)
và x+2=y+1=z+3
\(\left(x-\frac{1}{3}\right)\left(y-\frac{1}{2}\right)\left(z-5\right)=0\)
\(\Rightarrow\hept{\begin{cases}x=\frac{1}{3}\\y=\frac{1}{2}\\z=5\end{cases}}\)
Vì \(z+3=y+1\Rightarrow y=7\)
Lại có \(y+1=x+2\Rightarrow x=8-2=6\)
Vậy x = 6 ; y = 7 ; z = 5
Tim x,y,z biet:
\(x+1=y+2=z+3và\left(x-\frac{1}{5}\right)\left(y+\frac{1}{3}\right)\left(z-6\right)=0\)
Tim x,biet;
a/ \(\left(x-1\right)^2=0\)
b/ \(\left(x-2\right)^2-1=0\)
c/\(\left(2x-1\right)^3=-8\)
d/ \(\left(x+2\right)^2+1=0\)
a) \(\left(x-1\right)^2=0\Leftrightarrow x-1=0\Leftrightarrow x=1\) vậy \(x=1\)
b) \(\left(x-2\right)^2-1=0\Leftrightarrow\left(x-2\right)^2=1\) \(\Leftrightarrow\left\{{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=3\\x=1\end{matrix}\right.\) vậy \(x=3;x=1\)
c) \(\left(2x-1\right)^3=-8\Leftrightarrow2x-1=\sqrt[3]{-8}\Leftrightarrow2x-1=-2\)
\(\Leftrightarrow2x=-1\Leftrightarrow x=\dfrac{-1}{2}\) vậy \(x=\dfrac{-1}{2}\)
d) \(\left(x+2\right)^2+1=0\Leftrightarrow\left(x+2\right)^2=-1\) (vô lí)
vậy phương trình vô nghiệm
a) (x-1)2 = 0
<=> x-1 = 0
<=> x = 1
b) (x-2)2 - 1 = 0
<=> (x-2)2 = 1
<=> \(\left\{{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
<=> \(\left\{{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
c) (2x-1)3 = -8
<=> (2x-1)3 = -23
<=> 2x - 1 = -2
<=> 2x = -1
<=> x = \(-\dfrac{1}{2}\)
d) (x+2)2 + 1 = 0
<=> (x+2)2 = -1
<=> x+2 = -1
<=> x = -3
a, \(\left(x-1\right)^2=0\)
\(\Leftrightarrow\left(x-1\right)^2=0^2\)
\(\Leftrightarrow x-1=0\)
\(\Leftrightarrow x=1\)
Vậy ......
b, \(\left(x-2\right)^2-1=0\)
\(\Leftrightarrow\left(x-2\right)^2=1\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(x-2\right)^2=1^2\\\left(x-2\right)^2=\left(-1\right)^2\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
Vậy .....
c, \(\left(2x-1\right)^3=-8\)
\(\Leftrightarrow\left(2x-1\right)^3=\left(-2\right)^3\)
\(\Leftrightarrow2x-1=-2\)
\(\Leftrightarrow2x=-3\)
\(\Leftrightarrow x=-\dfrac{3}{2}\)
Vậy ...
d, \(\left(x+2\right)^2+1=0\)
\(\Leftrightarrow\left(x+2\right)^2=-1\)
\(\Leftrightarrow\) ko tìm dc giá trị của x thỏa mãn (do \(\left(x+2\right)^2\ge0\))
Tim x biet \(\left(x-5\right)^{x+1}-\left(x-5\right)^{x+21}=0\)
=> (x-5)x+1-(x-5)x+1+20=0
=> (x-5)x+1.1 - (x-5)x+1.(x-5)20=0
=> (x-5)x+1.[1-(x-5)20 ]=0
=> (x-5)x+1 = 0 hoặc 1-(x-5)20=0
=> x-5 = 0 hoặc (x-5)20 = 1
=> x=5 hoặc x-5=1
=> x=5 hoặc x=6.
tim x biet \((x^2-20)\times\left(x^2-15\right)\left(x^2-10\right)\left(x^2-5\right)< 0\)
tim x,y biet
a)\(\left|x-1\right|+\left|3-x\right|=\frac{6}{\left|y+3\right|+3}\)
bai 1: Tim x biet
\(\hept{\begin{cases}x-y=\frac{3}{10}\\y\left(x-y\right)=-\frac{3}{50}\end{cases}}\)
bai 2: Tim x, y biet:
x+\(\left(-\frac{31}{12}\right)^2\)=\(\left(\frac{49}{12}\right)^2\)-x=y2
Bai 9: Tim x,y,z biet:
(x-1)2+(x+y)2+(xy-z)2=0
a) thay \(x-y=\frac{3}{10}\)vào \(y\left(x-y\right)=\frac{-3}{50}\)ta có\(\frac{3}{10}y=\frac{-3}{50}\)=>\(y=\frac{-3}{50}:\frac{3}{10}=\frac{-1}{5}\)=>\(x-y=\frac{3}{10}\Rightarrow x=\frac{3}{10}+\frac{-1}{5}=\frac{1}{10}\)
hôm sau mik giải tip cho
Tim x biet, \(\left(x-2\right)\times\left(x+\frac{2}{3}\right)>0\)
Tim m de phuong trinh sau co dung 2 nghiem phan biet:
\(x^3-\left(1+m\right).x^2+\left(m-1\right).x+2m-2=0\)