4x²-x＝0
x(4x-1)＝0
x1＝0,x2＝1/4.
x²-6x+9＝(2x+3)²
(2x+3)²-(x-3)²＝0
(2x+3+x-3)(2x+3-x+3)＝0
3x(x+6)＝0
x1＝0,x2＝-6.
(3x-2)²＝(x+4)²
(3x-2-x-4)(3x-2+x+4)＝0
(2x-6)(4x+2)＝0
(x-3)(x+1/2)＝0
x1＝3,x2＝-1/2.