Question

Find all integers n such that n/(20-n) is a perfect square.

Answer 1

First figure out what numbers would actually work. 20-n needs to be positive in order for the entire fraction to remain positive, so that means x is between 1 and 20. Just plug in numbers and see what works. There are only 20 numbers to check.

Answer 2

right so n is {0,10,16,18}

Answer 3

it can be 0 or 10 too