The planar Tur\'an number of \K₄, ₅\

Let F be a set of graphs. The planar Tur\'an number, ex₏ (n, F), is the maximum number of edges in an n-vertex planar graph which does not contain any member of F as a subgraph. In this paper, we give upper bounds of ex₏ (n, \K₄, ₅\) 25/11 (n-2). We also give constructions which show the bounds are tight for infinitely many graphs.