on zagreb energy and edge-zagreb energy

in this paper, we obtain some upper and lower bounds for the general extended energy of a graph. as an application, we obtain few bounds for the (edge) zagreb energy of a graph. also, we deduce a relation between zagreb energy and edge-zagreb energy of a graph g with minimum degree δ≥2. a lower and upper bound for the spectral radius of the edge-zagreb matrix is obtained. finally, we give some methods to construct (edge) zagreb equienergetic graphs and show that there are (edge) zagreb equienergetic graphs of order n≥9.