A.12 h 6x = 0
B.- 2x + 14 =0
C.3x + 1 = 7x – 11
D.2x + x + 12 = 0
E.x – 5 = 3 – x
F.7 – 3x = 9 – x
G.5 – 3x = 6x + 7
H.11 – 2x = x – 1
I.15 – 8x = 9 – 5x
K.3 + 2x + 5 + 2x
A.12 h 6x = 0
B.- 2x + 14 =0
C.3x + 1 = 7x – 11
D.2x + x + 12 = 0
E.x – 5 = 3 – x
F.7 – 3x = 9 – x
G.5 – 3x = 6x + 7
H.11 – 2x = x – 1
I.15 – 8x = 9 – 5x
K.3 + 2x + 5 + 2x
A.12 -6x = 0
⇔ 6x = 12
⇔ x = 2
Vậy x= 2
B.- 2x + 14 =0
⇔ -2x = -14
⇔ x = 7
Vậy x= 7
C.3x + 1 = 7x – 11
⇔ 3x -7x = -11 -1
⇔ -4x = -12
⇔ x = 3
Vậy x= 3
D.2x + x + 12 = 0
⇔ 3x = -12
⇔ x = -4
Vậy x= -4
E.x – 5 = 3 – x
⇔ x +x= 3 +5
⇔ 2x = 8
⇔ x = 4
Vậy x= 4
F.7 – 3x = 9 – x
⇔ -3x +x = 9 -7
⇔ -2x = 2
⇔ x = -1
Vậy x= -1
G.5 – 3x = 6x + 7
⇔ -3x -6x = 7 -5
⇔ -9x = 2
⇔ x = -2/9
Vậy x= -2/9
H.11 – 2x = x – 1
⇔ -2x -x = -1 -11
⇔ -3x = -12
⇔ x = 4
Vậy x= 4
I.15 – 8x = 9 – 5x
⇔ -8x +5x = 9 -15
⇔ -3x = 6
⇔ x = -2
K.3 + 2x + 5 + 2x
⇔ 4x = -5 -3
⇔ 4x = -8
⇔ x = -2
a. 12+6x=0<=> 6x=-12<=> x=-2
B.-2x+12=0<=> -2x=-12 <=>x=6
C.3x +1=7x-11<=> 3x-7x=-1-11<=> -4x=-12<=> x=3
D.2x +x +12=0
<=>3x+12=0
<=>3x=-12
<=>x=-4
E.x-5=3-x
<=>x+x=3+5
<=>2x=8
<=>x=4
F. 7-3x=9-x
<=>x-3x=9-7
<=>-2x=2
<=>x=-1
G. 5-3x=6x+7
<=>-6x-3x=7-5
<=>-9x=2
<=>x=-2/9
H.11-2x=x-1
<=>-2x-x=-11+1
<=>-3x=-10
<=>x=10/3
l. 15-8x =9-5x
<=>-8x+5x=15-9
<=>-3x=6
<=>x=-2
K.3+2x+5+2x
<=>4x=-3-5
<=>4x=-8
<=>x=-2