Answer
$x=5; y=2$
Work Step by Step
Since we are given two equations
$2x-y= 8$ and $3x+4y=23$
Now, multiply the equation $2x-y= 8$ by $4$.
we have
$8x-4y= 32$ and $3x+4y=23$
After solving, we get $11x=55 \implies x=5$
Then, $3(5)+4y=23$
This implies $ 15+4y=23 \implies y=2$
Hence, $x=5; y=2$