ANSWER
The larger number is 18
EXPLANATION
Let x be the larger number and y be the smaller number.
Then,
[tex]x+y=12--(1)[/tex]
[tex]x-y=24--(2)[/tex]
Let us add equation (1) and (2).
[tex]2x=36[/tex]
Divide through by 2
[tex]x=18[/tex]
Put [tex]x=18[/tex] in to equation (1).
This implies that,
[tex]18=y=12[/tex]
[tex]y=12-18=-6[/tex]