3 and 2 should be the only roots
I count five 'k's there, so that part of the expression is
k⁵ .
Two 'n's form the rest of it, so that part is n² .
The parts are multiplied, so the simplest form of the expression is
k⁵ n² .
-15 is the smaller number because the further you go into the negatives like -30, -47, -52; youre getting further away from 0 and after 0 are positive numbers so -15 would be the smaller number
The formula for the circumference is 2πr.
The diameter d is given, which is 2 times the radius r (d = 2r)
So you have to calculate π d = 3.142×1.8 ≈ 5.7