Let 'x' be the age of Jose at the moment, x > 0. We need to find x.

Jose is x years old at the moment

30 years from now he will be x + 30 years old

12 years ago Jose was x - 12 years old

So we have

x + 30 = 8 * ( x - 12)

x + 30 = 8*x - 8*12

x + 30 = 8*x - 96

8*x - 96 = x + 30

8*x - x = 30 + 96

7*x = 126

x = 126/7

x = 18 years

Jose is 18 years old at the moment.