Bài 2:
a, 4x-10=0
<=>4x=10
<=>x=5/2
b,7-3x=9-x
<=>-3x+x=9-7
<=>-2x=2
<=>x=-1
c,2x-(3-5x)=4(x+3)
<=>2x-3+5x=4x+12
<=>2x+5x-4x=12+3
<=>3x=15
<=>x=5
d,5(2x-3)-4(5x-7)=19-2(x+11)
<=>10x-15-20x+28=19-2x-22
<=>10x-20x+2x=19-22+15-28
<=>-8x=-16
<=>x=2
Bài 3:
a,(x+2)(x-3)=0
<=>*x+2=0
*x-3=0
<=>*x=-2
*x=3
b,(x-1)(x+5)(-3x+8)=0
*x-1=0 *x=1
*x+5=0 <=> *x=-5
*-3x+8=0 *x=8/3
c,(5x+3)(x^2+4)(x-1)=0
*5x+3=0 *5x=-3 x=-3/5
*x^2+4=0<=> *x^2=-2^2<=> x=2
*x-1=0 *x=1 x=1
d,x(x^2-1)=0
<=>x=0 <=>x=0 <=>x=0
x^2-1=0 x^2=1 x=1
bài 4:
a,(4x-1)(x-3)=(x-3)(5x+2)
<=>4x^2-12x-x+3=5x^2+2x-15x-6
<=>4x^2-5x^2-12x-x-2x+15x=-6-3
<=>-x^2=-9
<=>-x^2=-3^2
<=>x=3
b,(x+3)(x-5)+(x+3)(3x-4)=0
<=>x^2-5x+3x-15+3x^2-4x+9x-12=0
<=>4x^2+3x-27=0
<=>x(4x+3)=27
<=>*x=27 <=>*x=27
*4x+3=27 *x=6
c,(2x-7)^2-6(2x-7)(x-3)=0
<=>4x^2-28x+49-12x^2+72x-108=0
<=>-8x^2+32x-59=0
<=>8x(x+4)=59
<=>*8x=59 <=>x=59/8
*x+4=59 x=55
d,x^2-5x+6=0
<=>x^2-x+6x+6=0
<=>x(x-1)-6(x-1)=0
<=>(x-1)(x-6)=0
<=>*x-1=0 <=>*x=1
*x-6=0 *x=6
