Please, use " ^ " to denote exponentiation. What I think you meant to share here is:
x^3*y^4(7x*y^5)
Here 7 is the only coefficient. Write that down: 7.
Next, let's focus on the x terms: x^3*x = x^4, so we now have 7x^4.
Finally, let's focus on the y terms: y^4*y^5 = y^(4+5) = y^9, so our final answer is
7x^4*y^9.
