I need help sizing a neutral grounding reactor so the Isc 3p=Isc SLG

Reactor sizing:

Isc SLG=3(E/1.73) / (x''d+x2+x0) and Isc 3p=(E/1.73)/x''d

3(E/1.73) / (x''d+x2+x0)= (E/1.73)/x''d

Add new reactance

3(E/1.73) / (x''d+x2+x0)+3xnew=(E/1.73)/x''d