Final answer:
In this question, we use mathematics to determine the number of 7th graders and 8th graders in the Kennedy Middle School student council.
Step-by-step explanation:
In this question, the subject is Mathematics and the grade is Middle School.
First, let's assign variables to represent the number of 7th graders and 8th graders in the student council. Let's say x is the number of 7th graders and y is the number of 8th graders.
According to the question, we have the equation y = 3x - 12. Since we know there are 48 students in total, we can write another equation: x + y = 48.
To solve this system of equations, we can substitute the value of y from the first equation into the second equation: x + (3x - 12) = 48. Simplifying the equation, we get 4x - 12 = 48. Adding 12 to both sides, we have 4x = 60. Dividing both sides by 4, we find x = 15. Substituting this value back into the equation y = 3x - 12, we find y = 3(15) - 12 = 45 - 12 = 33.
Therefore, there are 15 7th graders and 33 8th graders in the Kennedy Middle School student council.