We have a system of equations:
[tex]\begin{gathered} x+9=y \\ x=4y-6 \end{gathered}[/tex]
We can solve it by substitution, using the equality of the first equation, replacing y in the second equation:
[tex]\begin{gathered} x=4y-6 \\ x=4(x+9)-6 \\ x=4x+4\cdot9-6 \\ x=4x+36-6 \\ x=4x+30 \\ x-4x=30 \\ -3x=30 \\ x=-\frac{30}{3} \\ x=-10 \end{gathered}[/tex]
With the value of x, we can calculate y as:
[tex]y=x+9=-10+9=-1[/tex]
The solution expressed as ordered pair is (x,y) = (-10,-1).
Answer: (-10, -1)
