Решите уравнение (5x+1)(5x-1)-(5x+1)^2=0
25x^2 - 1 - (25x^2 + 10x + 1) = 0 25x^2 - 1 - 25x^2 - 10x - 1 = 0 - 10x - 2 = 0 - 10x = 2 10x = - 2 x = - 2/10 x = - 0,2