If the is lets say 5 years old, in 2 years, she will be 5 + 2 = 7 years old, and in 10 years 5 + 10 = 15 years old
so age in the future is the present age + how many years from now she will be
in this example the present age is 5 years old , if you replace that 5 with an x, the age in 10 years will be x + 10