Explanation
Correct answer: 40.
It's given that , where is the number of green tokens and is the number of red tokens won by one student and these tokens are worth a total of points. Since the equation represents the situation where the student won points with green tokens and red tokens for a total of points, each term on the left-hand side of the equation represents the number of points won for one of the colors. Since the coefficient of in the given equation is , a green token must be worth points. Similarly, since the coefficient of in the given equation is , a red token must be worth points. Therefore, a red token is worth points, or points, more than a green token.
Desmos solution:
Note: The coefficients 5 and 45 represent the points per green and red token, so the difference in value is 45-5.
Enter in Desmos:
Reviewed and rewritten by CookSAT