Which quadratic equation is equivalent to (x^2-1)^2 -11(x^2-1)+24=0
a)u^2-11u+24=0 where u=(x^2-1)
b) (u^2)^2 -11(u^2) +24 where u = (x^2-1)
c)u^2+1-11u+24 =0 where u =(x^2-1)
d)(u^2-1)^2 -11(u^2-1) +24 where u =(x^2-1)