( x - 7 ). ( x + 2 ) < 0
=> 2 số nguyên trên là 2 số nguyên khác dấu
Mà x + 2 > x - 7 với moi x E Z
=> x + 2 > 0 va x - 7 < 0
x - 2 > 0 x - 7 < 0
x < 0 + 7
x > 0 + 2 x < 7 ( 2 )
x > 2 ( 1)
Từ (1) Và (2) => 2 < x < 7
Ma x E Z => x E { 3,4,5,6}
Vay x E { 3,4,5,6}
k mik nha
Tìm x :
1) -12 + 3 . ( -x +7 ) = -18
2) x . ( x + 7 ) = 0
3) ( -x + 5 ) . ( 3 - x ) = 0
4) ( x + 12 ) . ( x - 3 ) = 0
5) x . ( 2 + x ) . ( 7 - x ) = 0
6) ( x - 1 ) . ( x + 2 ) . ( -x - 3 ) = 0
tìm x
x.(x+7)=0
(x+12).(x-3)=0
(-x+5).(3-x)=0
x.(2+x).(7-x)=0
(x-1).(x+2).(-x-3)=0
Tìm x
1. x(x+7)=0
2. (x+12)(x-3)=0
3. (-x+5)(3-x)=0
4. x(2+x)(7-x)=0
5. (x-1)(x+2)(-x-3)=0
tìm x
1/ x.(x+7)=0
2/ (x+12).(x-3)=0
3/ (-x+5).(3-x)=0
4/ x.(2+x).(7-x)=0
5/ (x-1).(x+2).(-x-3)=0
Bài 1: Tìm x
1/(2.x-5)+17=6
2/10-2.(4-3x)=-4
3/-12+3.(-x+7)=-18
4/24:(3.x-2)=-3
5/-45:5.(-3-2.x)=3
6/x.(x+7)=0
7/(x+12).(x-3)=0
8/(-x+5).(3-x)=0
9/x.(2+x).(7-x)=0
10/(x-1).(x+2).(-x-3)=0
bài 1: Tìm x
x.(x+7)=0
(x+12).(x-3)=0
(-x+5).(3-x)=0
x.(2+x).(7-x)=0
(x-1).(x+2).(-x-3)=0(làm đc 2 like)
a) (x^2-5) . (y^2-25) =0
b) (x^2+7) . (x^2 - 49 ) < 0
c) (x^2 -7 ) . ( x^2 - 49 ) <0
Tìm các số nguyên x , sao cho :
a) (x^2+5)×(x^2-25)=0
b) ( x^2-5) ( x^2-25)<0
c) (x-2)×( x+1)=0
d) ( x^2+7)× ( x^2-49)<0
e) ( x^2-7) × ( x^2-49) <0
Tìm x:
a) x.x+7)=0
b) (x+12).(x-3)=0
c) (-5+5).(3-x)=0
d)x.(2+x).(7-x)=0
e) (x-1).(x-2).(-x-3)=0
tìm x là số nguyên biết :
a) ( x-2).(x+1) = 0
b) ( x^2+7).(x^2+49)<0
c) (x^2-7).(x^2- 49) < 0
