$\"\"$

\

The equations are $\"\"$ and $\"\"$ .

\

$\"\"$ Equation (1)

\

$\"\"$ Equation (2)

\

Solve the second equation for y.

\

$\"\"$ (Add 3x to each side)

\

$\"\"$

\

$\"\"$

\

Since $\"\"$ , substitute $\"\"$ for y in the first equation.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ (Subtract 9 from each side)

\

$\"\"$

\

$\"\"$

\

$\"\"$ (Multiply each side by negative one) \ \

\

$\"\"$

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

The solution is $\"\"$ .