Verified Answer :

⇒ x³y⁴ × x⁵y³
⇒ x³⁺⁵y⁴⁺³
⇒ x⁸y⁷

In short, Your Answer would be x⁸y⁷

Hope this helps!

You have to add together the same veriables.
x[tex] x^{3} y^{2} X x^{5}y^{3}

 = x^{(3+5)} X y^{(2+3)}
  = x^{8}y^{5}