I'm having alot of trouble with the following:

2 types of sacks

Large sacks weigh 30kg

Small sacks weigh 24kg

There are 3 times as much small sacks than there are large ones

The total weight of sacks is 714kg

How many large/small sacks are there?

All ive been able to do is

30x+24y=714

not sure how to continue

Please help