Answer
The solution is $(8,-7)$.
Work Step by Step
The given system of equations is
$\Rightarrow 2x-y=23$ ...... (1)
$\Rightarrow x-9=-1$ ...... (2)
Isolate $x$ in equation (2).
$\Rightarrow x=-1+9$
$\Rightarrow x=8$
Substitute $8$ for $x$ in equation (1).
$\Rightarrow 2(8)-y=23$
Simplify.
$\Rightarrow 16-y=23$
Add $y-23$ to each side.
$\Rightarrow 16-y+y-23=23+y-23$
Simplify.
$\Rightarrow -7=y$
Check
Equation (1)
$\Rightarrow 2x-y=23$
$\Rightarrow 2(8)-(-7)=23$
$\Rightarrow 16+7=23$
$\Rightarrow 23=23$
True.
Check
Equation (2)
$\Rightarrow x-9=-1$
$\Rightarrow 8-9=-1$
$\Rightarrow -1=-1$
True.
Hence, the solution is $(8,-7)$.
