IF 31z5 is a multiple of 3,where z is a digit, what might be the value of z?

If 31z5 is a multiple of 9,where z is a digit,what is the value of z?You will find that there are two answers for the last problem.Why is this so?

If 31 a5 is a multiple of 3,where a is a digit,what could be the values of a?

If 24x is a multiple of 3,where x is a digit,what is the value of x?

If z is a complex number such that |z| gt 2 then the minimum value of |z+1/2|

If z is a complex number such that |z| ge 2 , then the minimum value of |z+(1)/(2)| .

If |z+4| le 3 , then the maximum value of |z+1| is

If z=(-2)/(1+sqrt(3) i) , then the value of arg z is

If z is any complex number such that |z+4|lt=3, then find the greatest value of |z+1|dot

If z^(2)+z+1=0 , where z is a complex number, then the value of (z+(1)/(z))^(2)+(z^(2)+(1)/(z^(2)))^(2)+(z^(3)+(1)/(z^(3)))^(2)+....+(z^(6)+(1)/(z^(6)))^(2) is

If z =10, find the value of z^3-3(z-10) ,