Answer: The correct option is (A) (12, 6).
Step-by-step explanation: Given that Sylvain spent a total of 18 hours on English and math homework over the last 3 weeks. He spent twice as much time on English than on math.
Let x represent the number of hours spent on English and y represent the number of hours spent on math.
The following system of equations will represent the given situation :

We are to find the solution of the given system of equations.
Substituting the value of x from equation (ii) in equation (i), we get

From equation (ii), we get

Thus, the required solution of the given system of equations is (x, y) = (12, 6).
Option (A) is CORRECT.