Answer: Choice B
n-4 = 32
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Step-by-step explanation:
We start with n students. The n is a placeholder for any positive whole number. After 4 of them drop the class, we're left with n-4 students.
Then we set that equal to 32, since that's the number of students left over.
This leads to the answer of n-4 = 32
Solving this equation gets us n = 36. We add 4 to both sides.