Choose one of the equations, then try and rewrite in terms of 1 Unknown, eg I've chosen XZ= 22 and am going to write it in terms of X
XZ = 22 Z = 22/X (this is writing Z in terms of X) So... X(22/X)= 22 22/X=22X 22 = 22X^2 (* ^2 is to the power 2) Therefore X = 1 And Z= 22
Use this to solve the remaining equations
1xY = 4n + 3 22Y= 2n - 7 Then rearrange and do simultaneous equations
22Y - 66 = 88n 22Y + 7 = 2n -73 = 86n n = -73/86
It is very very likely that I have made a mistake somewhere here given the strange number I have for n but I spent far too long on this not to post it ahaha, even if the numbers are incorrect this is the general method I would follow