6. Andy scored 90 on the last history exam. He scored 81 this time. By what percent did his score decrease?
1 answer:
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Answer:
6
Step-by-step explanation:
The expression can be rearranged to ...
b = 3 -9/(a+5)
In order for b to be an integer, (a+5) must be an integer divisor of 9. There are exactly 6 of those: ±1, ±3, ±9.
The attached table shows the values (a, b) = (x₁, f(x₁)).
