The equations are
\ (equation 1)
(equation 2)
Since
Rewrite the first equation for x.
\ (Subtract 2x from each side)
(Commutative property:
)
(Additive inverse property:
)
(Additive identity property:
)
\
Now Substitute for y in either equation to find the value of x.
(equation 2)
(replace
)
(Product of two same signs is positive)
(Commutative property:
) \ \
(Add:
)
(Add 9 to each side)
(Additive inverse property:
)
(Additive identity property:
)
(Add:
)
(Divide each side by 6)
(Cancel common terms)
(Divide:
)
\
Now
(replace y by
)
(Product of two same signs is positive)
The solution is
The solution is .