Is this the equation and also what is the anwser

18-20z 

Well first off, always put the biggest number in front when subtracting.

So it would look like this:

20z-18

The steps on finding z:

Lets say O=Ohio and T for  Texas.

20=O( which is Ohio)
18=T (which is Texas)

So all we do know is Substitute 20 and 18

20=T-18

Answer would be 38 because we did the opposite form (Subtract~ Add)
(the equation looks good.) 
Hoped I helped. 

 

Ab=dc ac=de ad=bce i hope this !