The equations are
\
(Equation 1)
(Equation 2)
Since
, substitute
for y in the first equation.
(Equation 1)
(Replace
)
Distrubiute terms using distributive property:
.

(Multiply:
)
(Add:
)
Apply addition property of equality: Add 24 to each side.
\
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add:
)
Apply division property of equality: Divide each side by 25.
\
(Cancel common terms)
(Divide:
)
Now Substitute 3 for x in either equation to find the value of y.
\
(Equation 2)
(Replace x by 3)
(Multiply:
)
(Subtract:
)
The solution is 
The solution is
.