(5x - 3)^2 = (x + 1)^2
5x - 3 = ± (x + 1)
5x - 3 = x + 1
4x = 4
x = 1 ；
5x - 3 = - x - 1
6x = 2
x = 2/3 .
即：
x1 = 1
x2 = 2/3