Question 1199801
{{{(a^2-3a-4)/(a^2-4)*(2-a-a^2) /(a^2-1)}}}


{{{((a + 1)(a - 4))/((a - 2)(a + 2))*(-(a + 2)(a - 1))/((a - 1)(a + 1))}}}


{{{((a + 1)(a - 4))/((a - 2)(a + 2))*(-(a + 2)cross((a - 1)))/(cross((a - 1))(a + 1))}}}



{{{((a + 1) (a - 4)(-(a + 2) ))/((a - 2) (a + 2) (a + 1))}}}


{{{(cross((a + 1)) (a - 4)(-cross((a + 2)) ))/((a - 2)cross( (a + 2))cross( (a + 1)))}}}


{{{((a - 4)(-1 ))/(a - 2)}}}


{{{-(a - 4)/(a - 2)}}}


{{{(4-a)/(a - 2)}}}