The equations are
\
(equation 1)
(equation 2)
Since 
Rewrite the second equation for x.
\
(Add 9 to each side)
(Additive inverse property:
)
(Additive identity property:
)
(Add:
)
Now Substitute 8 for x in either equation to find the value of y.
\
(equation 1)
(replace x by 8)
(Multiply:
)
(Subtract 16 from each side)
(Commutative property:
)
(Additive inverse property:
)
(Additive identity property:
)
(Subtract:
)
(Multiply each side by negative one)
(Product of two same signs is positive)
The solution is 
The solution is
.