It should be the other way around. So to translate to phrase who can establish an equation, follow this:
Your age ⇒ x
Your mother's age: 2x (twice your age)
Example of a problem to apply to this:
My mother's age is (present) twice my age. The sum of our ages is 60. Find our ages.
(My age) + (mother's age) = 60
(my age) + (twice my age) = 60
(x) + (2x) = 60
3x = 60
3x/3 = 60/3
x = 20
My age, x = 20 years
My mother, 2x = 2(20) = 40 years
ANSWER: My age is 20 years, and my mother is 40 years old.
Check: Sum of ages is 60.
20 + 40 = 60
60 = 60 (True)