(3x+1)^2 -(3x-1)^2 = 11x + 1,2
9x^2 + 6x + 1 - 9x^2 + 6x - 1 = 11x + 1,2
12x = 11x + 1,2
12x - 11x = 1,2
x = 1,2
(3x+1)^2 -(3x-1)^2 = 11x + 1,2
9x^2 + 6x + 1 - 9x^2 + 6x - 1 = 11x + 1,2
12x = 11x + 1,2
12x - 11x = 1,2
x = 1,2