Answer:she scored 69 points on the second test.
Explanation:
Let x represent the number of points that she scored on the second test.
She scored 12 points more on the first test than on the second test. It means that the number of points that she scored on the first test would be
x + 12
Therefore, the total number of points that she scored on both tests would be x + 12 + x = 2x + 12
Her mean score for both tests was 75
Mean = total points scored/number of tests
Therefore,
75 = (2x + 12)/2
2x + 12 = 150
2x = 150 - 12 = 138
x = 138/2 = 69