This is the concept of quadratic equations. We are required to find the missing factor in the partially factored quadratic equation given; n(n-3)+2(n-3)=()(n-3) here we proceed as follows; n(n-3)+2(n-3) when we factor this we get: (n-3)(n+2) this can be written as: (n+2)(n-3) The answer is (n+2)