\eqalign{ & {\text{If}}\,{\left( {\frac{a}{b}} \right)^{x - 1}} = {\left( {\frac{b}{a}} \right)^{x - 3}}, \cr & {\text{then}}\,{\text{the}}\,{\text{value}}\,{\text{of}}\,x\,{\text{is}} \cr} $$?

\eqalign{ & {\text{If}}\,{\left( {\frac{a}{b}} \right)^{x - 1}} = {\le

1.	\eqalign{ & {\text{If}}\,{\left( {\frac{a}{b}} \right)^{x - 1}} = {\left( {\frac{b}{a}} \right)^{x - 3}}, \cr & {\text{then}}\,{\text{the}}\,{\text{value}}\,{\text{of}}\,x\,{\text{is}} \cr} $$?
A.	1/2
B.	1
C.	2
D.	7/2
Answer» D. 7/2