The expression for the height is (3k - 5) Factorise the equation 6k^2 - 13k + 5 One is given : (2k-1). When factorising, you must make sure that you are obtaining the given equation. Here, to get 6k^2, 2k is multiplied with 3k. The other factor is (3k-x) Now, let's find x. From the factors (2k-1) (3k-x) how to obtain 13k?? Simple... 3k×-1 + 2k×x = 13k -3k + 2kx = 13k -3k + 2k(-5) = -3k + -10k = 13k So the other expression is (3k-5) which is the height.