Answer:
25 years old
Explanation:
Let the teacher's age be a.
Then:
a^2 - 23a = 50
In standard form, this quadratic is
x^2 - 23a - 50 = 0
Factoring this, we get (x - 25)(x + 2) = 0
So a is either 25 or a is -2. Only a = 25 is relevant here.
The teacher is 25 years old (Answer G)