Given a 3x3 grid arrange the integers 1-9 such that each row, column, and 3 element diagonal, sums to 15.

Really easy. You should immediately realize that 9,8, and 7 have to go on the diagonal.

never mind, diagonal also had to add to 15 lol

Start off by ensuring that no two numbers of 9,8, and 7 share a row, column, or diagonal. After that, it is easy.