Correct. $\displaystyle{9}{{k}}^{{2}}{\left({7}{{k}}^{{3}}+{3}{k}+{4}\right)}={9}{{k}}^{{2}}{\left({7}{{k}}^{{3}}\right)}+{9}{{k}}^{{2}}{\left({3}{k}\right)}+{9}{{k}}^{{2}}{\left({4}\right)}={63}{{k}}^{{5}}+{27}{{k}}^{{3}}+{36}{{k}}^{{2}}\usepackage{cmbright}\Huge\$

The missing exponent is 3.