1
<=> (x+3) (x-5)=0
<=>x+3=0 hay x-5 =0
<=>x=-3 hay x=5
2.
<=> 5x(x-1)=x-1
<=> 5x(x-1)-x+1=0
<=>5x(x-1)-(x-1) =0
<=>(x-1)(5x-1) =0
<=>x-1 =0 hay 5x-1=0
<=>x=1 hay x=1/5
3
<=>(x-2+4)(x-2-4)=0
<=>x-2+4=0 hay x-2-4=0
<=>x=-2 hay x=6
4
<=> (2x+1) -9 =0
<=> (2x+1 +9)( 2x+1 -9)=0
<=>2x+1 +9=0hay 2x+1 -9 =0
<=> x=-5 hay x= 4
5
<=>(2x-3+x+5) (2x-3-x-5)=0
<=>2x-3+x+5=0 hay 2x-3-x-5=0
<=> x=-2/3 hay x=8
6
<=>(1-3x+4-2x) (1-3x-4+2x) =0
<=> 1-3x+4-2x=0 hay 1-3x-4+2x=0
<=>x=1 hay x=-3
