1. a, 3.(x-1)-4=2.(x+1)-7 b,( 10-3x)/ 2= (6x+1)/ 3
⇔3x-3-4=2x+2-7 ⇔(10-3x).3=(6x+1).2
⇔3x-2x=2-7+3+4 ⇔ 30-9x =12x + 2
⇔ x = 2 ⇔-9x-12x=2-30
⇔-21x = -28
⇔ x= 4/ 3
c, (x-1)/ 4 +( x+1)/ 3=( x-1)/ 2
⇔(x-1).3.2 + (x+1).4.2 = (x-1).4.3
⇔6x-6 + 8x+8 = 12x-12
⇔6x+8x-12x = -12-8+6
⇔ 2x = -14
⇔ x= -7
d, x/ 3 + x =x/ 6 + (2x+1)/ 2
⇔ (x+3x)/ 3 = [2x+6.(2x+1)] /12
⇔(x+3x).12 = [2x+6.(2x+1)].3
⇔ 12x+36x = 6x+36x+18
⇔ 6x =18 ⇔ x = 3
e,( 3x+2)/ 2 -( 3x+1)/6 = 2x + 5/ 3
⇔ [(3x+2).6 - (3x+1).2]/12 = (2x.3+5)/3
⇔(18x+12-6x-2).3=(6x+5).12
⇔ 54x+36-18x-6 = 72x+60
⇔ -36x= 30
⇔x= -5/ 6
f, tương tự phần e nha bạn
2, a. (3x-5).(2x+7)=0
⇔ 3x-5=0 (h) 2x+7=0
⇔ x=5/3 (h) x=-7/2
b.⇔ x-2=0 (h) 2x+4=0 (h) 3x-5=0
⇔ x=±2 h x=5/3
c. ⇔2x²-6x=3x-9
⇔2x² -9x+9=0
⇔(x-3).(2x-3)=0
⇔ x=3 h x=3/2
d.⇔(4x-1).(3x+5-x+7)=0
⇔12x²+20x-4²+28x-3x-5+x-7=0
⇔8x² +46x-12=0
⇔(4x-1).(x+6)=0
⇔x=1/4 h x=-6
e. ⇔x²-6x+9-5x²+x+15x-3=0
⇔-4x²+10x+6=0
⇔ (2x+1).(x-3)=0
⇔x=-1/2 h x=3
f, ⇔2x²-x+12x-7=x²-49
⇔x²+11x+42=0
⇒ phương trình vô nghiệm