5x^2-10x+5= 5(x^2-2x+1)= 5(x-1)^2 a^2+2a+1-b^2= (a+1)^2-b^2

5x²-10x+5 = 5(x²-2x+1) = 5(x-1)² a²+2a+1-b² = (a+1)² - b² = (a+1-b) (a+1+b)