（x-1）（x+3）=12
x^2 + 2x - 3 = 12 ,x^2 + 2x - 15 = 0 = (x+5)(x-3)
x = 5 ,x = 3
(3x-5)(2x-1)= -12x+7 = 6x^2 - 13x + 5
6x^2 - x - 2 = 0 = (2x + 1)(3x - 2)
x = -1/2 ,x = 2/3
(6x+5)(6x-5)-24=0 = 36x^2 - 49 = (6x + 7)(6x - 7)
x = -7/6 ,x = 7/6
4(x-3)2-x(x-3)=0 = (x - 3)[4(x - 3) - x] = 3(x - 3)(x - 4)
x = 3 ,x = 4