What are the solutions of x^2 + 121 = 0? a. -11, 11 b. 11, 11i c. 11, -11i d. -11i, 11i

To solve this question you need to set up the equation and simplify
x^2 +121 = 0     you need to get the x^2 by itself so subtract 121
x^2 = -121   Now take the square root of both sides. but you can;t take the square root of a negative number which is where the i comes into play. 
 x= + -  11 i