(5x-1)^2 = (5x-1)(5x-1) = (5x)(5x) + (5x)(-1) + (-1)(5x) + (-1)(-1)= 25x^2 - 5x - 5x + 1= 25x^2 - 10x + 1
(5x-1)^2 = (5x-1)(5x-1) = (5x)(5x) + (5x)(-1) + (-1)(5x) + (-1)(-1)
= 25x^2 - 5x - 5x + 1
= 25x^2 - 10x + 1