(2x - 4).(x + 4) < 0
+) 2x - 4 < 0; x + 4 > 0
=> 2x < 4; x > -4
=> x < 2; x > -4
=> -4 < x < 2
=> x thuộc {-3; -2; -1; 0; 1}
+) 2x - 4 > 0; x + 4 < 0
=> 2x > 4; x < -4
=> x > 2; x < -4
=> 2 < x < -4 (vô lí)
Vậy...
a) (x-1).(x+2)=0
b) (x+4).(4-x)=0
c) (x+4)(-3x+9)=0
d) (2x-4)(x+3)=0
e) (x2-9).(2x+10)=0
g) (4-x).x2=0
1,x=3x2
2,(x+5)(x-3)-(x-30)=0
3,(2x-6)(x+4)+2(2x-6)=0
4,(2x-5)(x+9)+6x-15=0
3,(2x-5)(x+6)+8x-20=0
Tìm x
(2x-7)+17=6
12-2.(3-3x)=-2
-14+3.(-x+5)=-20
-90:5.(-3-2x)=6
(x+1).(x-3)=0
(2x-2).(x+4)=0
(22+4).(x+3)=0
(5-x).(6-2x)=0
3.(x+1)+5=x+8
-4.(2x+9)-(-8x+3)-(x+13)=0
a 3(x+1)-2(3x-4)=-13
b 2(x-3)-4(2x-1)=-20
c 2x(x+3)=0
d (x-1)(5x-x)=0
e (x+3)^2(4-x)=0
1) (x + 1/2).(2/3 - 2x) = 0 2) 2/3x + 1/2x = 5/2 : 3 và 3/4 3) (2x - 3)(6 - 2x)= 0 4) -5(x + 1/5) - 1/2(x - 2/3) = 3/2x - 5/6
a,(x-4)(2x-3)>0
b,(x-1)(2x+5)<0
c,(2x-3)(4-5x)=0
Các bn giúp mk vs nha!!!
Tìm các số nguyên x, biết:
a) 7x . ( x - 10 ) = 0
b) 17 . ( 3x - 6 ) . ( 2x - 18 ) =0
c) ( 4 - 2x ) . ( x - 3 ) = 0
d) - x . ( x + 7 ) . ( x - 4 ) = 0
1.
a.|2x+4|+|4x+8|=0|2x+4|+|4x+8|=0
b.|x−5|+|x−7|=0|x−5|+|x−7|=0
c.|x+8|−|2x+2|=0
Tìm x, y thuộc Z , biết :
a) ( 2x - 10 ) ^ 2 + ( 4 - 2y ) ^ 2 = 0
b) ( x - 2 ) . ( x + 3 ) > 0
c) ( x - 2 ) . ( x + 3 ) < 0
d) ( 2x - 6 ) . ( x - 5 ) > 0
e) ( 2x - 6 ) . ( x - 5 ) <0
f) ( x + 4 ) . ( 2 - x ) < 0
g) ( x + 4 ) . ( 2 - x ) > 0
h) ( x ^ 2 + 3 ) . ( 5x + 20 ) < 0
