Answer
$(31/4, -1/8)$
Work Step by Step
We know that $y=x/2 -4$ Thus, in the second equation, wherever we see y, we will substitute x/2 -4, and then we will solve:
$3x+ 2(x/2 -4) =23 \\\\ 4x-8=23 \\\\ 4x=31 \\\\ x=31/4$
We now substitute x=31/4 back in:
$y=(31/4)/2 -4 = -1/8$
We plug our values for x and y back into the first equation and confirm that our answer is, indeed, correct.