Question 736466
Make sure you include instructions with your problem on what it asks you to do so we don't have to guess. 
x^4 + 3x^2 - 4 =0
(x^2 + 4)(x^2 - 1) =0
(x^2 + 4)(x+1)(x-1) =0

x^2 + 4=0 or x+1 =0 or x-1=0 
x^2 = -4 or x+1 =0 or x-1=0 solve for x
x=2i or x=-1 or x=1