Question 124693
the factors of (a+1)^2 = ( a+1)(a+1)
the factors of (a-1)^2= (a-1)(a-1)
the factors of a^2-1 = (a+1)(a-1)
therefore the LCD = ( a+1)(a+1)(a-1)(a-1)
or (a+1)^2(a-1)^2