bài 2
a) 3(3x-1)=3x+5
9x-3 = 3x+5
9x-3x = 5+3
6x =8
x =4/3
b)(3x-1)^2-3(3x-2)=9(x+1)(x-3)
3x^2-6x+1-9x+6=9x^2-27x+9x-27
3x^2-6x-9x-9x^2+27x-9x=-27-1-6
-6x^2+3x = -34
-6x^2+3x+34=0
c) 3x(2x-3)-3(3+2x^2)=0
6x^2-9x-9-6x^2 = 0
-9x-9 = 0
-9(x+1) =0
=> x+1 =0
x =-1
d)(x-1)^2-x(x+1)+3(x-2)+5=0
x^2-2x+`1-x^2-x+3x-6+5 = 0
x =0