tim x thuoc Z (x+2).(3-x) >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}
1 )Tim x, y thuoc Z
x + y = x.y
2) Tim x thuoc Z
(x + 1)+(x+3)+(x+5)+...+(x+99)=0(x-3)+(x-2)+(x-1)+...+10+11=11-12(x-5)+7(3-x)=530(x+2)-6(x-5)-24x=100x + y = x.y
=> xy - x - y = 0
=> (xy - x) - y + 1 = 1
=> x(y - 1) - (y - 1) = 1
=> (x - 1)(y - 1) = 1
=> x - 1 = y - 1 = 1 hoặc x - 1 = y - 1 = -1
=> x = y = 2 hoặc x = y = 0
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}
a/[x-2][7-x] > 0 . tim x thuoc Z
b/[x mu 2+13][x mu 2-17] > 0 . tim x thuoc Z
c/[x mu 2-13][x mu 2-17] <0 . tim x thuoc Z
GIUP MINH VOI
NGAY KIA MINH DI BOI DUONG ROI
CAM ON CAC BAN NEU CAC BAB GIUP MINH
a, => [x-2] và [7-x] cùng dấu
Xét 2 trường hợp cùng >0 và cùng<0
b, tương tự
c, xét 2 trường hợp khác dấu
Có gì ko h bạn cứ hỏi nha!
Tim x biet
(x-2)(x+3)<0 voi x thuoc z
Tim x thuoc Z
1/ x(x+3)=0
2/ (x-2)(5-x)=0
3/(x-1)(x2+1)=0
dễ thôi
1/ x(x+3)=0 2/ (x-2)(5-x)=0 3/(x-1)(x2+1)=0
=> x=0 hoặc x+3=0 => x-2=0 hoặc 5-x=0 => x-1=0 hoặc x2+1=0
TH1: x=0 TH2: x+3=0 TH1: x-2=0 TH2: 5-x=0 TH1: x-1=0 TH2: x2+1=0
=> x= -3 => x=2 => x=5 => x=1 => x2 =-1
vậy x thuộc {0; -3} Vậy x thuộc { 2; 5 } =>x2=(-1)2 hoặc x2=12
TH1: x2=(-1)2 TH2: x2=12
=> x= -1 =>x=1
vậy x thuộc { 1; -1 }
tích cho mình nha bài mình làm đúng đấy
a)x(x+3)=0
=>x=0 hoặc x+3=0
x=0-3
x=-3
b)(x-2)(5-x)=0
=>x-2=0 hoặc 5-x=0
x=0+2 x=5-0
x=2 x=5
3)(x-1)(x2+1)=0
=>x-1=0 hoặc x2+1=0
x=0+1 x2=0-1=-1 mà x2>=0(với mọi x) (loại)
x=1
Vậy x=1
a)x(x+3)=0
=>x=0 hoặc x+3=0
x=0-3
x=-3
b)(x-2)(5-x)=0
=>x-2=0 hoặc 5-x=0
x=0+2 x=5-0
x=2 x=5
3)(x-1)(x2+1)=0
=>x-1=0 hoặc x2+1=0
x=0+1 x2=0-1=-1 mà x2>=0(với mọi x) (loại)
x=1
Vậy x=1
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