1) tim x thuoc z
/x+2/=4
tim x thuoc Z biet :
(x-1)^2 =(x-3)^4
HELP ME:0!!
\(\left(x-1\right)^2=\left(x-3\right)^4\)
\(\Leftrightarrow\left(x-1\right)^2-\left(x-3\right)^4=0\)
\(\Leftrightarrow\left(x-1\right)^2-\left[\left(x-3\right)^2\right]^2=0\)
\(\Leftrightarrow\left[\left(x-1\right)-\left(x-3\right)^2\right]\left[\left(x-1\right)+\left(x-3\right)^2\right]=0\)
\(\Leftrightarrow\left(x-1-x^2+6x-9\right)\left(x-1+x^2-6x+9\right)=0\)
\(\Leftrightarrow\left(-x^2+7x-10\right)\left(x^2-5x+8\right)=0\)
\(\Leftrightarrow-\left(x-5\right)\left(x-2\right)\left(x^2-5x+8\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=0\\x-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=2\end{matrix}\right.\)
Vậy: ...
(x-1)^2 =(x-3)^4=\(\left\{{}\begin{matrix}1+1\\2+2\\3+3\\4+4\end{matrix}\right.=2+4+6+8=\sqrt[]{251234=\Sigma\dfrac{2}{2}22\dfrac{2}{2}}\max\limits_{212}=\dfrac{21}{23}2123=\sum\limits1^{ }_{ }\text{(x-1)^2 =x=}\sum1\)
Bổ sung cho @ Huỳnh Thanh Phong.
(- \(x^2\) + 7\(x\) - 10).(\(x^2\) - 5\(x\) + 8) = 0
(- \(x^2\) + 5\(x\) + 2\(x\) - 10).(\(x^2\) - \(\dfrac{5}{2}\)\(x\) - \(\dfrac{5}{2}\)\(x\) + \(\dfrac{25}{4}\) + \(\dfrac{7}{4}\)) = 0
[(- \(x^2\) + 5\(x\)) + (2\(x\) - 10)].[(\(x^2\) - \(\dfrac{5}{2}\)\(x\)) - (\(\dfrac{5}{2}\)\(x\) - \(\dfrac{25}{4}\)) + \(\dfrac{7}{4}\)] = 0
[ -\(x\)(\(x\) - 5) + 2.(\(x\) - 5)]. [\(x\)(\(x\) - \(\dfrac{5}{2}\)) - \(\dfrac{5}{2}\).(\(x\) - \(\dfrac{5}{2}\)) + \(\dfrac{7}{4}\)] = 0
(\(x\) - 5).(-\(x\) + 2).[(\(x-\dfrac{5}{2}\)).(\(x\) - \(\dfrac{5}{2}\)) + \(\dfrac{7}{4}\)] = 0
(\(x\) - 5).(-\(x\) + 2).[(\(x\) - \(\dfrac{5}{2}\))2 + \(\dfrac{7}{4}\)] = 0 (1)
Vì (\(x\) - \(\dfrac{5}{2}\))2 ≥ 0 ⇒ (\(x\) - \(\dfrac{5}{2}\))2 + \(\dfrac{7}{4}\) ≥ \(\dfrac{7}{4}\) (2)
Kết hợp (1) và (2) ta có:
\(\left[{}\begin{matrix}x-5=0\\-x+2=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=5\\x=2\end{matrix}\right.\)
Vậy \(x\in\) {2; 5}
Tim x thuoc Z
1< /x+2/ <4
1</x+2/<4
Suy ra /x+2/={2;3}
/x+2/=2 suy ra x+2=2 hoặc x+2=-2
x =2-2 x =(-2)-2
x=0 x =-4
/x+2/=3 suy ra x+2=3 hoặc x+2=-3
x=3-2 x=(-3)-2
x=1 x=-5
PS:cái dưới của mình là sai nhé
tim x thuoc z
a) 4 ( x - 1 ) ( 3x + 2 ) = 16
Tim x thuoc Z de A thuoc Z va tim gia tri do .
a/ A= x+3/x-2 .
b/ A= 1-2x/x+3 .
cho P=(2x-1)(x+2)/(2x+1)
Tim x thuoc Z để P thuoc Z
tim x y thuoc z biết | x -1| + |y | = 2
( x -1) mu 2 + y mu 2 = 4
1)
tim x thuoc Z biet x2=25
2)tim gia tri nho nhat cua (x-2005)2+4
1)\(x^2=25\Rightarrow\left|x\right|=5\Rightarrow\int^{x=5}_{x=-5}\)
2)\(\left(x-2005\right)^2\ge0\Rightarrow\left(x-2005\right)^2+4\ge4\)
Dấu "=" xảy ra <=> x=2005
tick nhé
x2 = 25
x2 = (-5)2 = 52
x thuộc {-5 ; 5}
(x - 2005)2 + 4 có GTNN
(x - 2005)2 + 4 \(\ge\) 4
Vậy GTNN (x-2005)2 + 4 = 4
Khi x -2005= 0 => x = 2005
tim x , y thuoc Z
|x+2|.|y-1|-4|y-1|=0
|x-2|+|(x-2).(y+5)|=0
tim x thuoc z biet
(x-1)(x-3)=-5
(x+1)(x+4)=0
(x^2-4)(x^2-19)<0
a)=>x-1;x-3 \(\in\)Ư(-5)={-1;-5;1;5}
còn lại thử từng TH nhé
b)\(\Rightarrow\orbr{\begin{cases}x+1=0\\x+4=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=-1\\x=-4\end{cases}}\)
c)=>x2-4;x2-19 trái dấu
Ta có:x^2-4-(x^2-19)=x^2-4-x^2+19=15 >0
\(\Rightarrow\orbr{\begin{cases}x^2-4>0\\x^2-19< 0\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x^2>4\\x^2< 19\end{cases}}\)
Ta có:4<x^2<19
=>x^2\(\in\){9;16}
=>x\(\in\){3;4}