tim x thuoc Z biet x*(x-1) > 0
tim x thuoc Z biet x^3-x^2+x-1=0
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, y thuoc Z biet : | x-2| + (x-y+1)^2 =0
Có 2 Th | x-2| , (x-y+1)^2 =0
| x-2| , (x-y+1)^2 là hai số đối ; lx-2/ nguyên dương => ( x - y + 1 )^2 là số nguyên âm
TH1 | x-2| , (x-y+1)^2 =0
=> x = 2 để /x-2/ = 0
thay vào bên kia ta có : ( 2 - y + 1 ) ^2 = 0 => 2 - y + 1 = 0 => 3 - y = 0 => y = 3
TH2 : Tự xét nha bn
tim x,y,z thuoc z biet /x/+/y/+/z/=0
VÌ \(\left|x\right|\ge0;\left|y\right|\ge0;\left|z\right|\ge0\)NÊN ĐỂ\(\left|x\right|+\left|y\right|+\left|z\right|=0\)\(\Leftrightarrow\hept{\begin{cases}\left|x\right|=0\\\left|y\right|=0\\\left|z\right|=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=0\\y=0\\z=0\end{cases}}}\)
cho P =|x|.(y-1).Tim x,y thuoc Z biet P<0
tim x thuoc Z biet (x-7)x(x+3)<0
tim x thuoc z biet
a) (x-1)(x+2) < 0
b) (x+3)(x-5) > 0
a) (x-1).(x+2) < 0
TH1: x - 1< 0
x < 1
TH2: x + 2 < 0
x < -2
b) ( x +3).(x-5) > 0
TH1: x + 3 > 0
x> -3
TH2: x - 5 > 0
x > 5
KL: x > 5
Tim X thuoc Z biet :
(x-3).(x+2)<0
(x - 3).(x + 2) < 0
=> x - 3 và x + 2 trái dấu
Mà x + 2 > x - 3
=> x + 2 > 0 => x > -2
x - 3 < 0 => x < 3
=> -2 < x < 3, mà x thuộc Z => x \(\in\) {-1;0;1;2}
tim x thuoc z,biet
(x-5)^2=0
\(\left(x-5\right)^2=0\)
\(\Rightarrow x-5=0\)
\(\Rightarrow x=0+5\)
\(\Rightarrow x=5\)
Vậy x=5
(x - 5)2 = 0
=> (x - 5)2 = 02
=> x - 5 = 0
=> x = 0 + 5
=> x = 5
Vậy x = 5
(x - 5)2 = 0
=> (x - 5)2 = 02
=> x - 5 = 0
=> x = 0 + 5
=> x = 5