The polynomial -15x^2+157x+14,500 represents the electricity generated (in gigawatts) by geothermal sources during 2002-2007. The polynomial 893x^2-80x+10,229 represents the electricity generated (in gigawatts) by wind power during 2002-2007. In both polynomials, x represents the number of years after 2002. Find a polynomial for the total electricity generated by both geothermal and wind power during 2002-2007.