let x represent the number of cups of additional cups of sugar and y represents the total number of pies she can bake.
Given that;
"Laura has already baked 9 pies, and she can bake 2 pies with each additional cup of sugar she buys"
With 14 additional cups of sugar;
substituting the value of x;
Therefore, the total number of pies Laura can Bake with 14 additional cups of sugar is;