4(3x^2+2)^2-7(3x^2+2)-11=0

(3xˇ2 +2)=t 4tˇ2- 7t-11=0 t1=11/4, t2=-1 a)3xˇ2 +2 = 11/4,12xˇ2+8=11, xˇ2= 1/4, x1=1/2, x2=-1/2 b)3xˇ2+2 = -1, 3xˇ2=-3,xˇ2=-1, x3 =i,x4=-i iˇ2 =-1