Morgan is 15 years younger than Ms. Santos. Their combined ages is 44

Let their two ages be s and s-15. Then s + s-15 = 44 = 2s-15.

Then 2s = 59, and s = 29 1/2 years.

Morgan's age is (29 1/2 - 15) years, or 14 1/2 years.

Ms. Santos' age is 29 1/2 years.

Do 14 1/2 and 29 1/2 add up to 44? YES

Ms. Santos would be 29 years old