It is a right triangle so you can use the Pythagorean theorem.
3² + 4² = FG²
9 + 16 = FG²
25 = FG²
√25 = FG
5 = FG
Hope this helps :)
The product of the greatest common divisor and the least common multiple of two numbers is always the product of the two numbers. So, you have
It would be x^5-1 fjjbdbxjwjxjs