Solve:

Q. Solve for x if ${\mathrm{x}}^{{\mathrm{a}}^3}. {\mathrm{x}}^{{\mathrm{b}}^3}.{\mathrm{x}}^{3\mathrm{ab}\left(\mathrm{a} +\mathrm{b}\right)}={\left(2^5\right)}^{25}$, and a + b = 5.