Question

Trevor, currently 22 years old, is half of his dad's age six years ago. How old is Trevor's Dad? Choose the equation that would find Trevor's Dad's age, d.

Answer 1

Just walk through this problem one variable at a time.
Trevor is 22 yrs old, T = 22
Trevor's dad's age is unknown, we'll label him d
Trevor is half of his dad's age six years ago.
From the aforementioned statement, we can say that T = d -6
The d represents his dad, and the -6 is subtracting six years from the dad's age.
Since you know T and you have the equation, you can substitute and find the value of d.