Answer :
1. 8000-x (You invest x in the first, then you have 8000-x more to make up for)
2. 0.02x (Interest * how much you invested)
3. 0.03(8000-x) (Interest * how much you invested)
4. 0.02x+240-0.03x
=240-0.01x
2. 0.02x (Interest * how much you invested)
3. 0.03(8000-x) (Interest * how much you invested)
4. 0.02x+240-0.03x
=240-0.01x