
The given funtion is
and 
Compare the above two equations.
\We get,
\
(Subtract 9 from each side) \ \
(Additive inverse property:
) \ \
(Additive inverse property:
)
(Subtract:
)
(Multiply each side by negative one)
(Product of two same signs is positive)
(Divide each side by 7) \ \
(Cancel common terms) \ \
(Divide:
)
The value of
.