I think you meant "y = 4 arccot (x)."
This is equivalent to:
y
---- = arccot x
4
and so cot (y/4) = x
first polygon
ext. angle=180°-120°
=60°

n=360°/60°
n=6
second polygon
n=2(6)=12
ext. ang= 360°/n = 360°/12° = 30°
int. ang = 180°-30°= 150°
answer is C
Hello,
multiple of 9 betheen 50 and 99 are :54,63,72,81,99
and 54,72 are even.
5-4=1 and not 5
7-2=5 ok
72 is the number searched.
The answer would be A because each side is being multiplied by 3
Change 5/3 to 15/9. Then add 15 + 17 and put it over 9. 32/9