Final answer:
The expression that represents the number of pencils each student received is (3p - 5)/7.
Step-by-step explanation:
To find the number of pencils each student received, we need to calculate the total number of pencils minus the number of pencils Mrs. Murillo kept. The expression that represents this is (3p - 5) divided by the number of students, which is 7. Therefore, the correct expression is (3p - 5)/7. Option d) (3(p + 5)/7) is incorrect because it includes an extra 5 pencils which were kept by Mrs. Murillo.