Answer:
True, the scores are not valid.
Step-by-step explanation:
The test supposed to be measuring intelligence. We can assume that the intelligence of most people relatively stable (will not change too much over a short amount of time), and can expect it should go upward with brain growth and education. But the test seems to give a huge decrease from the first and second results. Then the third result is a huge increase that even higher than the first test.
We don't know the true value of the subject, but seeing the huge gap for every repetition we can tell that the test result lacks precision.
The next number in the linear pattern would be 18
3 x^3 y^2
_______
8 ( y/x-3/2)
