Add the polynomials:

(6x53x3+7x4)+(2x5+11x4+4x2+12)\displaystyle {\left({6}{x}^{{5}}-{3}{x}^{{3}}+{7}{x}-{4}\right)}+{\left(-{2}{x}^{{5}}+{11}{x}^{{4}}+{4}{x}^{{2}}+{12}\right)}