Answer :

Using elimination you can eliminate 'y' to find x first.
4x=24
+ 5x=12
-------------
9x=36
9/9 x=36/9
X=4

Next use substitution to plug 4 back in to 'x'

4(4)+y=24
16+y=24
-16 -16
------------
Y=8
X is 4 and Y is 8