Convert the complex number `-(5 sqrt(3))/2 + 5/2 i` to polar form. Give exact answers for `r` and `theta` (no decimals).

Box 1: Enter your answer as a complex number in a+bi form. Example: 2+5i
Enter each value as a number (like 5, -3, 2.2172) or as a calculation (like 5/3, 2^3, 5+4)
Enter DNE for Does Not Exist, oo for Infinity
Decimal values are not allowed